Spinach, Mushroom, Swiss Cheese, And Egg Casserole

This delectable vegetarian dish is a cross between a frittata, a souffle, a quiche, and a casserole.  The last time I made this delicious dish was when I made my daughter Randi’s bridal shower.  This dish made an incredible hit, and many people asked me for the recipe.  I like to make this because I can do most of the prep work a day in advance, and then it’s a breeze to pop it into the oven.  This is a wonderful dish for a brunch or a family breakfast, or for a special occasion.  You will love this!

  • 1 Tbsp. oil (I use any olive oil for this)
  • 1 large or 2 medium onions, diced
  • 10 oz. mushrooms, sliced, and brushed off or lightly rinsed and dried (use your favorite mushrooms- I usually use white)
  • 9-10 oz. prewashed baby spinach
  • 10 extra large or jumbo eggs
  • 2 cups shredded Swiss or Gruyere cheese (about 8-10 oz. -I like to use a combination of the two cheeses, but that isn’t necessary) – then divide your cheese in half
  • 1 cup of half and half 
  • Kosher salt
  • freshly cracked black pepper
  • cayenne or red pepper flakes – optional

You can do this part of the prep in advance and then refrigerate until you are ready to bake:

Grease sides and bottom of a 9 x 13 rectangular or oval baking dish with butter or margarine.

Heat oil in large saute pan on medium high until oil is hot.  If you are using crushed red pepper flakes for a little heat, sprinkle about 1/2 teaspoon of them into the oil.   Add onions; saute 2-3 minutes until translucent. Add mushrooms; saute 5 minutes until the mushrooms are starting to brown a little.  Add about 1 teaspoon salt and about 15-20 grinds of black pepper (about 1/2 teaspoon), and if you are using the cayenne instead of the red pepper flakes, sprinkle about 1/4 teaspoon in. Turn off the heat.  Add the spinach, and mix in so that the spinach wilts and turns a darker color.  Spread the onion, spinach, mushroom mixture in the bottom of the greased baking dish; top with half of the shredded cheese.  This can now be covered and put into the fridge until you are ready to bake it. 

When you are ready to bake, follow these steps:

Preheat oven to 350 degrees. 

Beat eggs with half and half in mixing bowl. Add a little more salt and pepper to taste (about 1/2 teaspoon of each).  Pour the egg mixture over the vegetables and cheese; top with the remaining 1 cup of shredded cheese.

Bake 35-40 minutes until eggs are puffed and set and top is lightly browned.  You should not see any liquid from the eggs.  If you do, bake another 5-10 minutes.  If the top isn’t browned, turn the setting in the oven to broil, and cook 1-2 minutes, but watch very carefully so you don’t burn this masterpiece!

Serve immediately!  

Note:  You can do all the preparation and then bake this at the same time.  But if you are making this for company, doing the prep work a few hours in advance or the night before takes all the anxiety away.