Mushroom Casserole - Healthy Recipes Blog (2024)

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Last updated: · Recipes developed by Vered DeLeeuw and nutritionally reviewed by Rachel Benight MS, RD · This website generates income via ads and uses cookies.

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This deliciously cheesy mushroom casserole is wonderfully flavored with onions, thyme, and melted gruyere.

Made without breadcrumbs and ready in about 40 minutes, it's keto and gluten-free.

Mushroom Casserole - Healthy Recipes Blog (1)

This casserole is amazing. It's so cheesy and flavorful! The wonderful aroma it releases when you cook it will let you know how good it's going to be.

Mushrooms are one of my favorite vegetables (well, technically they're fungi, not vegetables). And this tasty casserole is one of my favorite ways to cook them.

Jump to:
  • Ingredients
  • Instructions
  • Expert tip
  • Frequently asked questions
  • Variations
  • Serving suggestions
  • Storing leftovers
  • Related recipes
  • Foodie Newsletter
  • Recipe Card

Ingredients

You'll only need a few simple ingredients to make this mushroom casserole. The exact measurements are included in the recipe card below. Here's an overview of what you'll need:

Olive oil: A delicious oil and one of my favorites to cook with. It does have a relatively low smoke point, so you can use avocado oil instead.

Baby Bella mushrooms: You can also use white mushrooms if that's all you can find.

Salt and pepper: I use kosher salt in most of my recipes. If using fine salt, you will need to reduce the amount you use.

Aromatics: Onions and garlic. While jarred minced garlic is convenient, freshly minced tastes significantly better.

Spices: I use dried thyme and parsley.

Shredded Gruyere cheese: Gruyere tastes best, but I've made this casserole with shredded sharp cheddar and it was good too.

Mushroom Casserole - Healthy Recipes Blog (2)

Instructions

Since mushrooms release quite a bit of liquid when cooked, you can't just put them in a dish and bake them. You need to saute them first.

So to make this recipe, I saute the mushrooms and chopped onions in olive oil until the mushrooms have released their liquid and most of the liquid has evaporated.

Mushroom Casserole - Healthy Recipes Blog (3)

Check out the video below in the recipe card to see the process. See the steam? That's the mushroom's liquid, evaporating.

Once the liquid has mostly evaporated, you can transfer the mushrooms and onions to a greased baking dish, top them with cheese, and bake the casserole until the cheese has melted.

Mushroom Casserole - Healthy Recipes Blog (4)

Expert tip

If your casserole dish is broiler-safe, you can simply broil the casserole for 2-3 minutes, in the middle of the oven, until the cheese is melted. You don't want to get too close to the heating element and risk burning the casserole.

Frequently asked questions

What mushroom variety should I use?

I like to use brown mushrooms in this recipe because it makes the casserole look more presentable than white mushrooms. So I use baby Bella or crimini mushrooms.

I use quite a lot of mushrooms - 32 oz. But keep in mind that mushrooms lose significant volume after they are cooked. Once cooked, they fit nicely in a 2-quart casserole dish.

Since I'm lazy, I buy pre-sliced mushrooms at Whole Foods. I also buy pre-chopped onions. Which makes this casserole super easy!

What cheese is best in this casserole?

Gruyere goes wonderfully with mushrooms. But sometimes, when I have an open bag of pre-shredded Italian cheeses in the fridge, I use that instead.

Another tasty option is smoked gouda. It adds a wonderfully smoky flavor to the casserole.

Can I skip sauteing the mushrooms and simply bake them?

No, unfortunately, that won't work. As explained above, mushrooms release quite a bit of liquid when cooked, so you can't just put them in a dish and bake them. You need to saute them first and get rid of some of that liquid.

Variations

A good way to vary this recipe is by using different cheeses, such as cheddar, gouda, or provolone.

Another way is to experiment with different herbs and spices. Good options include smoked paprika, ground cumin, and dried oregano.

Serving suggestions

Mushrooms go well with steak, so I often make this recipe when I serve reverse-seared steak or London broil.

They are also excellent with chicken. Sometimes I slice baked chicken breast and top the slices with this casserole.

Since the mushrooms are not very colorful, it's nice to have a colorful veggie as a side, such as steamed broccoli or tomato salad.

Storing leftovers

Once the leftovers are cool, transfer them with a slotted spoon to an airtight container. Keep them in the fridge for up to 4 days. Reheat them in the microwave at 50% power.

Mushroom Casserole - Healthy Recipes Blog (5)
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Recipe Card

Mushroom Casserole - Healthy Recipes Blog (10)

4.99 from 447 votes

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Cheesy Mushroom Casserole

This deliciously cheesy mushroom casserole is wonderfully flavored with onions, thyme, and melted gruyere.

Prep Time10 minutes mins

Cook Time30 minutes mins

Total Time40 minutes mins

Course: Side Dish

Cuisine: American

Servings: 6 servings

Calories: 200kcal

Author: Vered DeLeeuw

Ingredients

  • ¼ cup olive oil plus more for the pan
  • 32 oz baby Bella or crimini mushrooms sliced
  • 2 teaspoons Diamond Crystal kosher salt or 1 teaspoon of fine salt
  • 1 cup onions chopped
  • 1 tablespoon fresh garlic minced
  • ½ teaspoon black pepper
  • ½ teaspoon dried thyme
  • 1 cup Gruyere cheese shredded
  • 1 teaspoon dried parsley for garnish

Instructions

  • Preheat your oven to 400 degrees F. Grease a 2-quart baking dish with olive oil.

  • Heat the olive oil in a large, deep skillet over medium-high heat. Add the mushrooms, onions, and kosher salt. Cook, stirring occasionally, until the mushrooms have released their liquid and the liquids have mostly evaporated, about 10 minutes.

  • Add the garlic, black pepper, and thyme. Cook, stirring, for one more minute. Remove from heat.

  • Transfer the mixture to the prepared baking dish. Sprinkle it with the shredded cheese.

  • Bake the casserole until hot and bubbly, about 15 minutes. Sprinkle with parsley and serve.

Video

Notes

If your casserole dish is broiler-safe, you can simply broil the casserole for 2-3 minutes, in the middle of the oven, until the cheese is melted. You don't want to get too close to the heating element and risk burning the casserole.

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Nutrition per Serving

Calories: 200kcal | Carbohydrates: 8g | Protein: 10g | Fat: 15g | Saturated Fat: 5g | Sodium: 441mg | Fiber: 2g | Sugar: 4g

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Disclaimers

Cup measurements refer to the standard American cup, which is 240 milliliters. Most of my recipes are low-carb (or keto) and gluten-free, but some are not. Please verify that a recipe fits your needs before using it. Recommended and linked products are not guaranteed to be gluten-free. Nutrition info is approximate, and the carb count excludes non-nutritive sweeteners. Nutrition info may contain errors, so please verify it independently. Recipes may contain errors, so please use your common sense when following them. Please read these Terms of Use carefully before using any of my recipes.

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About the Author

Mushroom Casserole - Healthy Recipes Blog (21) Vered DeLeeuw, LL.M., CNC, has been following a low-carb real-food diet and blogging about it since 2011. She's a Certified Nutrition Coach (NASM-CNC), has taken courses at the Harvard School of Public Health, and has earned a Nutrition and Healthy Living Certificate from Cornell University. Her work has appeared in several major media outlets, including Healthline, HuffPost, Today, Women's Health, Shape, and Country Living. Click to learn more about Vered.

Reader Interactions

Comments

    Leave a Comment

  1. Lynn

    Mushroom Casserole - Healthy Recipes Blog (22)
    Who would have thought to combine cheese with mushrooms?!! But this works! We all enjoyed this as one of our sides for dinner guests; it was such a nice addition to other vegetables, in a non-competitive way. I used sliced portobello mushrooms which also gave a lovely flavour. Thank you..who would have thought?! 🙂

    Reply

    • Vered DeLeeuw

      I'm so glad you liked this recipe, Lynn! I love the idea of using portobello mushrooms.

      Reply

  2. Leslie

    Mushroom Casserole - Healthy Recipes Blog (23)
    Oh, Sooo Good!!

    Reply

    • Vered DeLeeuw

      Glad you liked it, Leslie!

      Reply

  3. Lynn

    Mushroom Casserole - Healthy Recipes Blog (24)
    Our love of mushrooms knows no bounds, so when we saw this recipe, we knew we had to try it at our pre-Christmas gathering and it was a hit! I didn't change a thing, assembled it early in the day and because oven space was at a premium, simply nuked it to melt the cheese and reheat the mushrooms; as a make-ahead dish...full marks! Thank you for publishing this yummy recipe!

    Reply

    • Vered DeLeeuw

      I'm so glad this recipe was a success, Lynn! It's interesting to learn that you can microwave it to melt the cheese. Thank you for this tip.

      Reply

  4. Patty

    Mushroom Casserole - Healthy Recipes Blog (25)
    I made this and it was a hit with my family. I’m going out of town and would like to bring this as a side dish. Can I make this, put it in a baking dish, refrigerate it and then bake it the next day? Thanks!

    Reply

    • Vered DeLeeuw

      Yes, absolutely. If I were you, I would pre-cook the mushroom/onion mixture (steps 2,3) and put it in a food storage container. Bring the shredded cheese in a separate bag or container. When ready to bake the casserole, grease the baking dish, assemble the casserole (drain any liquids from the mushroom/onion mixture before adding it to the baking dish), and bake it.

      Reply

  5. Lija

    Mushroom Casserole - Healthy Recipes Blog (26)
    I'm a mushroom lover, so I can't wait to try this recipe. I liked your tip to broil rather than bake the casserole for 2-3 minutes until the cheese is melted. I was thinking I could actually use my air fryer that's like a toaster oven instead of lighting the big oven.
    Also, since I always stir-fry mushrooms and onions when we have steak, I am looking forward to using this recipe when the husband grills steaks again. Thanks for the advice!

    Reply

    • Vered DeLeeuw

      You're very welcome, Lija! I hope you enjoy it.

      Reply

Mushroom Casserole - Healthy Recipes Blog (2024)

FAQs

What is the key to making a good casserole? ›

  1. Choose the right baking dish. If you're all about the crunchy topping, use a shallow dish. ...
  2. Undercook your pasta. ...
  3. Drain your meat. ...
  4. Beware of mushy vegetables. ...
  5. Know your cheeses. ...
  6. Master the art of casserole assembly. ...
  7. Don't skip the topping. ...
  8. Make it now, but bake it later.
Nov 1, 2021

What is the best substitute for cream of mushroom soup in green bean casserole? ›

How do you make Green Bean Casserole from scratch without using any canned soup or cream-of mushroom? Use a simple bechamel sauce, maybe a bit thinner than you otherwise would. If you're so inclined, slice some of your favorite mushrooms in it.

What is in casserole dish? ›

In the United States, a casserole or hot dish is typically a baked food with three main components: pieces of meat (such as chicken or ground meat) or fish (such as tuna) or other protein (such as beans or tofu), various chopped or canned vegetables (such as green beans or peas), and a starchy binder (such as flour, ...

Can you freeze cooked mushroom & spinach? ›

There was not time to wait, I had to replenish, so here I am dedicating my whole day to a full freezer of tasty mushrooms. Green leafy vegetables like spinach are perfect to prepare that way as well and freeze-up for later. It's a great way to cook those vegetables only once and enjoy them for the months to come.

What are 5 components of a casserole? ›

Let's talk anatomy: A standard dinner casserole usually includes a protein, a starch, a vegetable, a sauce (or other binding ingredient), and cheese. But making a casserole is not an exact science, and you can definitely break away from this formula. Check out some fun side-dish casseroles and desserts below!

What are three guidelines to follow when preparing casseroles? ›

Top tips for casseroles
  1. Cut your ingredients, such as meat, potatoes and parsnips, into similar-sized pieces to ensure they cook evenly. ...
  2. To save time – and washing up – use a flameproof, ovenproof casserole dish. ...
  3. Avoid adding flour after cooking or the raw flour taste will remain.

How do you thicken homemade mushroom soup? ›

You can thicken soup by adding flour, cornstarch, or another starchy substitute. For the best results, never add flour or cornstarch directly to your soup. If you do, it will clump up on top. Instead, ladle a small amount of broth into a separate bowl and let it cool.

What can you use to thicken mushroom soup? ›

Adding extra cream can thicken a creamy or blended soup like this wild mushroom-soup, but stirring in a spoonful of thick yogurt can be more effective. Be careful not to boil the soup once you've added the cream or yogurt or it may split.

What is a substitute for heavy cream in mushroom soup? ›

Milk + cornstarch

To replace one cup of heavy cream, mix 2 tablespoons cornstarch into 1 cup milk, whisking well to break up any clumps. Cornstarch requires heat to thicken, so add the slurry to soups and sauces and simmer for at least 1 minute to activate the cornstarch.

What is the difference between a stew and a casserole? ›

There is little difference between a casserole and a stew. A purist would say that a casserole goes in the oven, heating the dish from all directions, while a stew goes on the stovetop and is heated from the bottom. Another point of difference is a casserole is the name of the pot used for cooking.

Why put foil on casserole dish? ›

It protects your food from drying out or burning and helps keep in the heat and moisture, ensuring a perfectly cooked meal. Loosely covering your dish with foil can prevent uneven browning while baking. However, tightly sealing your bakeware with foil is the way to go for more steam.

What is the oldest known casserole? ›

Macaroni and cheese is the oldest written casserole recipe found in 1250.

Can you freeze an egg? ›

According to the USDA Food Safety and Inspection Service (FSIS), you can freeze eggs for up to one year. When you're ready to use frozen eggs, thaw them overnight in the refrigerator or under running cold water. Use egg yolks or whole eggs as soon as they're thawed.

Can I freeze potatoes? ›

You absolutely can freeze potatoes, and you should if you have an excess of spuds. But there's one important thing to remember: You should really only freeze cooked or partially cooked potatoes, as raw potatoes contain a lot of water. This water freezes and, when thawed, makes the potatoes mushy and grainy.

Can I freeze carrots? ›

Freezing carrots is such a great way to avoid waste. It will also make cooking them a little quicker from frozen. Like most vegetables, if frozen raw, the texture, taste, colour and nutritional value of carrots deteriorates. Make sure you blanch the veg to preserve these elements.

How can I improve my casserole? ›

Many casseroles seem to improve in flavour if kept overnight (cool them quickly and keep them in a refrigerator, by the way, once they're cold). This means it's quite possible to make two casseroles while the oven is in full swing, and keep one for the next day.

What are the 4 parts of a casserole? ›

Not every single casserole has all of them, but as a rule of thumb, here's what to look for: a starch, a binding agent or sauce, and a protein or vegetable. Many casseroles also have both vegetables and proteins, as well as a crunchy element to give some textural contrast, and cheese.

What are 3 possible advantages to preparing your own casseroles? ›

Why You Should Be Cooking More Casseroles
  1. They're versatile. For every set of tastebuds, there's a casserole to match. ...
  2. They can be nutritious. ...
  3. They're easy, from prep through cleanup. ...
  4. They feed a crowd. ...
  5. They're transportable and gift-able.

How do you make a casserole not soggy? ›

To prevent a soggy top and a firm or crunchy bottom, it's important to use a shallow baking dish, to cook the casserole at the correct oven temperature and for the appropriate amount of time, and to be mindful of the amount of liquid used in the recipe.

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