Mushroom and Feta Breakfast Casserole

Mushroom and Feta Breakfast Casserole has two of my very favorite ingredients in a low-carb breakfast casserole! And I think this is a perfect combination of flavors in an egg casserole, and this popular recipe is also Keto and gluten-free.

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This favorite Mushroom and Feta Breakfast Casserole is a recipe I’ve made over and over through the years! And if I had to choose out of all the breakfast casseroles on my blog, this would probably be my pick. There’s something about the combination of mushrooms and feta that sounds like a perfect breakfast to me. And recently I decided this recipe needed new photos, so today I am happy to share the new-and-improved pictures!

This recipe has been super popular through the years! It’s also a sentimental favorite because I’ve made it for quite a few guests, both at my house in Salt Lake and the one in Bountiful. I’ve even made this for some food blogger houseguests, and it always got good reviews.

The original version of this made 10 servings, and you can see that printer-friendly recipe back in the archives. But even though this keeps at least a week in the fridge and reheats well, a few years back I shared this smaller version that makes six servings. That’s the size I make most often now, and probably the one most people will want.

I’ve made this through the years without many changes, which is rare for me! But I confess I do often use a bit more Feta than the recipe calls for. But Feta Cheese has barely any carbs, so that’s something I don’t consider as much of a splurge! If you like mushrooms and Feta Cheese, I hope you make this Kalyn’s Kitchen classic immediately if you haven’t tried it!

What ingredients do you need for this recipe:

(This is only a list of ingredients; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete 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!

What mushrooms did I use for the Mushroom Feta Breakfast?

I used brown Cremini mushrooms for this recipe, but seriously any mushrooms you find in your store will be delicious in this!

How low in carbs is the Mushroom and Feta Breakfast Casserole?

This breakfast with eggs, mushrooms, Feta, and green onions has only 3 net carbs per serving with 17 grams of protein!

How to Make Mushroom and Feta Breakfast Casserole:

(This is only a summary of the steps for the recipe; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)

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 cook the mushrooms until they release their liquid and get slightly brown.
3. While mushrooms cook, beat eggs with milk until they’re well-combined.
4. Spray a baking dish with non-stick spray or olive oil and put mushrooms in the dish.
5. Put Feta and green onions over the mushrooms. (This photo shows the slightly increased amount of Feta I prefer these days.)
6. Pour eggs over the mushrooms, Feta, and green onions. 
7. Then use a fork to gently “stir” so the ingredients are well distributed in the eggs.
8. Bake at 375F/190C about 30 minutes, or until eggs are set and starting to slightly brown.
9. Serve hot, with some sour cream on top if desired.

Make it for a Low-Carb Meal:

The breakfast casserole with mushrooms and Feta cheese would be delicious with one of these low-carb breads on the side, and some of them cook at the same temperature:

• Savory Breakfast Muffins
• Savory Almond Flour Bread (This needs a lower temperature than the breakfast casserole so make it ahead.)
• Almond Flour Zucchini Muffins

More Low-Carb Breakfast Recipes:

• Keto Breakfasts the Family Will Eat
• Keto Breakfasts to Bake on the Weekend and Eat All Week
• Crustless Keto Quiche Recipes

Weekend Food Prep:

This Mushroom Feta breakfast recipe has been added to a category called Weekend Food Prep  where you’ll find recipes you can prep or cook on the weekend and eat during the week!

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4.6 Stars (37 Reviews)

Yield: 6 generous servings

Mushroom and Feta Breakfast Casserole

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. This recipe makes 6 servings, but see the link in NOTES if you prefer the original recipe for 10 servings!

Ingredients

• 12 eggs
• 1 T half and half (Probably optional, but I usually use it if I have some.)
• 1 pound, washed and sliced mushrooms (see notes)
• 2 tsp. olive oil (or more, depending on your pan)
• 1 cup crumbled Feta cheese (or more, see notes)
• 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

Instructions

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.
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. While mushrooms cook slice green onions and crumble the Feta cheese.
5. Beat eggs with milk until the yolks and whites are completely combined.
6. Layer the mushrooms, Feta, and green onions (if using) into the casserole dish.
7. Then pour eggs over mushroom-Feta-onion mixture. Gently stir with a fork so that mushrooms. cheese, and onions are evenly distributed in the mixture. 
8. 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 sodium.)
9. Bake 30-35 minutes, or until eggs are completely set and the top is starting to brown.  Serve hot.
10. This cheesy breakfast casserole with mushrooms 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.

Notes

I like brown Cremini mushrooms for this recipe, but any mushrooms will work. Use more mushrooms if you like. Use heavy cream or milk instead of half and half, or skip it completely, whichever you prefer.

I often use more Feta Cheese in this, even as much as 1 1/2 cups. For me that just makes it better!

To make the larger size of this favorite breakfast recipe, Click Here for 10 Servings Size Printer Friendly Recipe.

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

Nutrition Information

Yield

6

Serving Size

1
Amount Per Serving Calories 276Total Fat 20gSaturated Fat 10gUnsaturated Fat 10gCholesterol 411mgSodium 599mgCarbohydrates 4gFiber 0gSugar 3gProtein 19g

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.

Did you make this recipe?

Did you make this recipe? Please leave a star rating (under the PRINT button in the recipe) or share a photo of your results on Instagram! THANKS!

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

Find More Recipes Like This One:
Use Breakfast Recipes to find more recipes like this one. Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.

Historical Notes for this Recipe:
The Mushroom Feta Breakfast Casserole was first posted in 2006! It was updated several times through the years, and was last updated with more information and better photos in 2026.