Kalyn's Kitchen

Mushroom and Feta Breakfast Casserole

Mushroom and Feta Breakfast Casserole has two of my very favorite ingredients in a low-carb breakfast casserole! And this recipe is also Keto and gluten-free.

PIN this savory breakfast casserole to try it later.

Mushroom and Feta Breakfast Casserole finished casserole in baking dish

This favorite Mushroom and Feta Breakfast Casserole is one that I’ve made over and over through the years, and if I was forced to choose only one breakfast casserole out of the many different ones I’ve shared here, this might be the one I’d choose. There’s something about the combination of mushrooms and feta that sounds like a perfect breakfast to me.

This recipe is also a sentimental favorite because back in 2008 I made Low-Carb Mushroom and Feta Breakfast Casserole for breakfast when Genie from The Inadvertent Gardener stopped for a night as she was headed for California. Then last summer Genie stayed at my house again with her husband and son! I think I made this breakfast casserole for her that time, but she did tell me how much she has enjoyed the Mushroom and Feta Breakfast Casserole through the years.

This original recipe for this made 10 servings, and it keeps for at least a week in the fridge, and reheats well. I included the printer-friendly link to that larger version in this updated recipe, but the photos here are for a smaller version of Mushroom and Feta Breakfast Casserole that makes 6 generous servings, and that’s the size I make most often now.

And did you know that Feta Cheese has barely any carbs! If like mushrooms and Feta Cheese, please try this immediately if you haven’t already done so!

What ingredients do you need for this recipe:

  • eggs
  • half and half (optional)
  • mushrooms
  • olive oil
  • Feta cheese
  • green onions (optional)
  • Spike Seasoning (affiliate link), or any all-purpose seasoning blend
  • fresh ground black pepper to taste

What is Feta Cheese?

Feta is a brine-cured crumbly white cheese that comes from Greece, and it’s loved by people all over the world! Read more about Feta Cheese here if you’re interested. And Feta Cheese is one of the lowest carb cheeses you can find, which makes it perfect for a low-carb breakfast casserole like this!

Low-Carb Mushroom and Feta Breakfast Casserole process shots collage

How to Make Mushroom and Feta Breakfast Casserole:

(Scroll down for complete printable recipe, including nutritional information.)

  1. Wash mushrooms if needed, dry well, and cut into thick slices or half-slices.
  2. Heat the olive oil in a non-stick frying pan and saute the mushrooms until they release their liquid and get slightly brown.
  3. Spray a baking dish with non-stick spray or olive oil and put mushrooms in the dish.
  4. Put Feta and green onions over the mushrooms.
  5. Beat eggs until they’re well-combined; then pour eggs over and use a fork to gently “stir” so the ingredients are well distributed in the eggs.
  6. Bake at 375F/190C about 30 minutes, or until eggs are set and starting to slightly brown.
  7. Serve hot, with some sour cream on top if desired.

Low-Carb Mushroom and Feta Breakfast Casserole found on KalynsKitchen.com

More Low-Carb Breakfast Recipes to Try:

Kalyn’s Top Ten Low-Carb Breakfasts to Bake on the Weekend and Eat All Week
My Top Ten Favorite Low-Carb and Gluten-Free Eggs Recipes

Weekend Food Prep:

This recipe has been added to a new category called Weekend Food Prep  to help you find recipes you can prep or cook on the weekend and eat during the week!

Mushroom and Feta Breakfast Casserole

Mushroom and Feta Breakfast Casserole

Yield 6 generous servings
Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes

Mushroom and Feta Breakfast Casserole has two of my very favorite ingredients in a breakfast casserole that's low-carb, Keto, and gluten-free.


  • 12 eggs
  • 1 T half and half (Probably optional, but I usually use it if I have some in the house.)
  • 1 pound, washed and sliced mushrooms (see notes)
  • 2 tsp. olive oil (or more, depending on your pan)
  • 1 cup crumbled Feta cheese
  • 1/3 cup sliced green onions (optional, but good)
  • 1 tsp. Spike Seasoning, or use any all-purpose seasoning blend that’s good on eggs
  • fresh ground black pepper to taste


  1. Preheat oven to 375F/190C.  Spray 8.5 X 12 inch glass casserole dish with nonstick spray.
  2. Wash mushrooms and cut into thick slices or half slices. Slice green onions.
  3. Heat the olive oil in a non-stick frying pan,  then cook the mushrooms until they release their liquid and get slightly brown, about 5 minutes.
  4. Layer the mushrooms, Feta, and green onions (if using) into the casserole dish.
  5. Beat eggs with milk until the yolks and whites are completely combined, pour over mushroom-Feta-onion mixture, then stir gently with a fork so that mushrooms. cheese, and onions are evenly distributed in the egg mixture.  Season with Spike Seasoning (affiliate link) or other seasoning of your choice and fresh-ground black pepper. (I don’t add salt because Spike Seasoning and Feta both have some salt.)
  6. Bake 30-35 minutes, or until eggs are completely set and the top is starting to brown.  Serve hot.
  7. This will keep for at least a week in the fridge and can be reheated in a microwave or in a covered pan on the stove.


I like brown Cremini mushrooms for this recipe, but any mushrooms will work; use a few more mushrooms if you'd like. Use heavy cream or milk instead of half and half, or skip it completely, whichever you prefer.If you'd like to make a larger size for this favorite breakfast casserole, Click Here for 10 Servings Size Printer Friendly Recipe.

This recipe created by Kalyn and made many, many times through the years.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 240Total Fat: 17gSaturated Fat: 8gUnsaturated Fat: 9gCholesterol: 426mgSodium: 702mgCarbohydrates: 3gFiber: 0gSugar: 2gProtein: 17g

Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.

If you make this recipe I'd love to hear how it turns out. Leave a star rating or share on social media with the hashtag #KALYNSKITCHEN, thanks!

Low-Carb Mushroom and Feta Breakfast Casserole thumbnail photo

Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Egg dishes like this Low-Carb Mushroom and Feta Breakfast Casserole are great for low-carb diet plans, and also a perfect Low-Glycemic breakfast option for any phase of the South Beach Diet. And Feta cheese is extremely low in carbs!

Find More Recipes Like This One:
Use Breakfast Recipes to find more recipes like this one. Use the Recipes by Diet Type photo index pages to find more recipes suitable for a specific eating plan. You might also like to Follow Kalyn’s Kitchen on Pinterest to see all the good recipes I’m sharing there.

Pinterest image of Mushroom and Feta Breakfast Casserole

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    55 Comments on “Mushroom and Feta Breakfast Casserole”

  1. Have you ever tried to freeze this?  Thinking of making a big batch for quick dinners some nights.  This looks great.  Oh, I made your roasted carrots and mushrooms last week, I am addicted!

    • Glad you’re enjoying the recipes. I used to freeze this type of casserole, but when it thaws they release a lot of water so I don’t really prefer freezing them. They stay good in the fridge for a week or more though.

  2. This looks yummy !!! What other chesses would work well in this dish ?? A couple family members do not like feta ( more for me ..HAHA …) Any suggestions appreciated ! Thanks . Doris

  3. Great recipe! I actually just made your Mushroom Feta Baked Mini Frittatas earlier this month, and because the egg got stuck on my muffin tins, I made them in a 9×13 glass pan this week. So I essentially already did this recipe. It worked out so well, and I have been enjoying a slice of this casserole along with a few breakfast sausages every morning at work this week. It’s simple and keeps really well. 5 stars!

  4. Can I prepare this the night ahead so I can just put it in the oven the next day?

    • I haven’t ever done that. If you’re rushed for time in the morning I’d probably whip up the eggs, crumble the feta, and cook the mushrooms and keep them in separate containers. Then combine and cook in the morning. Having everything cold will also affect the cooking time.

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  7. YUUUM! This is everything I crave in a savory breakfast. Looks perfect for Thanksgiving morning!

  8. I have made this every year for Christmas brunch for the last three years. I and my family love it! I'm looking forward to another great brunch this Christmas. Thank you for a great recipe!

  9. My family loves feta cheese and this recipe would be a success.

  10. Alyce, not sure why your comment was so slow arriving in my e-mail, but hope you enjoy!

  11. Colleen, hope you enjoy!

  12. This looks delicious! I made your asparagus and artichoke casserole and loved it so I'm excited to try this as well!

  13. Ok, I've got it and printed it. Now to find a wonderful time to use it; it deserves a group to eat it. Thanks, Kalyn.

  14. How fun, tell her hello for me too!

  15. This was super yummy! I made it and then went to look at more of your recipes and my mother walked in and said, "Hey! I know Kalyn!" So, she told me to tell you, "Cizon says, 'Hello,' and the recipe was delicious."

  16. Sun-dried tomatoes sound like a great addition to me!

  17. I made this toady for a Coffee/Brunch gathering…..It was a hit! I added Sun-dried tomatoes because I'm addicted to them. So so good. I will be adding this to my favorites list. Thank you!

  18. i just made this for breakfast for the rest of the week. i just took a small bite and so far so good. let's see how it goes when i reheat it in the morning.

    btw, love your site.

  19. i'm going to make it , but not with 18 eggs….

  20. Kristy Girl, I bet that would be very tasty!