Spinach-Mushroom Breakfast Casserole

Are your mornings crazy as you rush around trying to get you and your family out the door for school or work? Are they so crazy that you don’t see how you can prepare a healthy breakfast much less have time to eat it?

Breakfast casserole witheggs, onions, spinach, and mushroomsCrustless egg casseroles are my go-to breakfast meal. I make the casserole over the weekend or during the evening and quickly reheat it in the morning while I am getting ready for the day.  Each 9 by 13 size recipe provides 8 servings which get my husband and me through 4 days of breakfasts. The casserole can be reheated in one of two ways:  zapped at “reheat” level in the microwave, or, if you’re not fond of microwaving, heated in a covered dish or aluminum foil in the oven or toaster oven.

One of our favorite breakfast casseroles is the Crustless Quiche with Spinach and Broccoli which I posted about some time ago. While delicious and low-carb, it is not dairy-free (containing both cream and cheese) and so does not qualify for Whole30 status which is how I am eating for the month of January. That called for a new breakfast casserole that would satisfy me and be so good I didn’t miss the cheese.

Enter the Spinach and Mushroom Breakfast Casserole!  A most nutritious breakfast that is delicious and satisfying while being dairy-free, grain-free and gluten-free.  Well balanced with protein, healthy fats, and power-packed vegetables, this casserole will fuel up your family for the morning and provide a substantial serving of greens.

Spinach Mushroom Breakfast Casserole with fork Spinach-Mushroom Breakfast Casserole

  •  1 1/3 cup chopped onions (or about one large onion)
  •  ¼ pound shiitake mushrooms
  • 2 tsp minced garlic
  • 1 tablespoon of coconut oil
  • 20 oz. frozen chopped spinach (thawed)
  • 18 eggs
  • 2 tablespoons chopped fresh basil
  • 1/8 tsp cayenne pepper (though I’m thinking of doubling this)
  • ½ tsp freshly ground pepper
  • 1 tsp sea salt

Grease a 9 x 13 pan with coconut oil or ghee and preheat oven to 350 degrees.

Chop onions and mince garlic and allow them to sit for 5 or 10 minutes to fully develop a chemical reaction that optimizes their health benefits.  Meanwhile, remove stems of mushrooms (and discard). Chop the heads of the mushrooms into small pieces.

Melt coconut oil in a pan over medium to medium–low heat. (I believe in gentle cooking.) Add the onions and mushrooms and cook until the onions are translucent – stirring occasionally. Add the garlic and cook for another minute. Remove from heat. Stir in the fresh basil. Squeeze water from the thawed spinach and add to the mushroom/onion mixture, stirring until well mixed. Spread the mixture evenly in the bottom of the 9 by 13 greased pan.

Scramble the eggs in a bowl with a wire whisk until the whites and yolks are completely combined. You could use a mixer for this, but why not get an arm workout while preparing this nutritious dish. Then whisk in the cayenne, pepper, and salt completely.

Pour the egg mixture over the spinach mixture in the pan and bake at 350 for approximately 40 minutes until a knife inserted in the middle comes out clean. Cut into 8 servings and serve immediately or allow to cool and then wrap and refrigerate for reheating. Will keep in the refrigerator for 4 or 5 days.

You could probably cook this in muffin pans also. I have not tried that yet, so if you do please post about your experience in the comments below.

 How do you manage a healthy breakfast during the work/school week? Give us your suggestions in the comment section, please!  Or join the discussion on the The Health Wish Facebook page while keeping up to date on new blog posts.

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  1. I’d fall in love with that much spinach! But unfortunately, I’m terribly allergic to mushrooms… Is there something else that could be substituted instead?

    • Sorry it has taken me a day to get back to you…

      I’ve been thinking about replacements for the mushrooms – there is not much that has the same texture, so substitutes will make it a slightly different taste, but that’s ok. I alter my recipes frequently based on what I have in my refrigerator. If I did not have mushrooms I would probably either just leave it out and continue with the rest of the recipe, or I would substitute a cup (more or less) of shredded carrots or finely chopped cauliflower or broccoli. You certainly could put in about a cup of any vegetable that sounds good to you. :) Let me know what you try (and enjoy the spinach!)

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  4. Cindy

    Instead of coconut oil, could I use olive oil? Since I’m from Louisiana, I will be putting more red and black pepper! Also, do you think I could use baby bella’s instead of shiitake mushrooms?

    • I see no reason why you couldn’t use olive oil. I would say you could use olive oil in any baking that you do at 400 degrees F or less; olive oil starts to smoke and break down above that.

      Also, any kind of mushrooms will work well! I do lots of substituting when I make a breakfast casserole to keep life interesting. :)


  5. Dee

    I love , love , love this recipe, thank you so much. It has become a staple in my diet ever since I came across this recipe about 6 months ago. I work in disabilities and now have several of my clients making it. It really is so simple, yet healthy and tasty. I have never left a comment on any site before nd yet today I felt the need to return and show my appreciation. A big thank you.

    • So glad you like it, Dee. Variations of it are a staple around my house too – my husband loves to take it camping. We cut it into large squares and wrap them separately for reheating. My husband calls them “breakfast bricks”.

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