Can I make this casserole ahead of time?

Yes, you can prepare the casserole the night before and refrigerate it. Simply bake it the next morning. This makes it an excellent choice for busy mornings or holiday brunches.

Can I use frozen spinach instead of fresh?

Yes, you can use frozen spinach. Just make sure to thaw and drain it well to remove excess moisture before adding it to the casserole.

Can I add other vegetables or meats?

Absolutely! This recipe is versatile. You can add diced bell peppers, onions, or even cooked bacon or sausage for extra flavor.

Is this casserole gluten-free?

Yes, as long as you use gluten-free ingredients, this egg casserole is naturally gluten-free. Always check the labels on pre-packaged items to be sure.

How do I store leftovers?

Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in the microwave or oven before serving.

Can I freeze the casserole?

Yes, you can freeze the baked casserole. Allow it to cool completely, then wrap it tightly with plastic wrap and aluminum foil. It can be frozen for up to 2 months. To reheat, thaw overnight in the refrigerator and bake until heated through.

How To Make The Perfect Spinach And Mushroom Egg Casserole

Ingredients

Scale

2 tablespoons olive oil
1 medium onion, finely chopped
2 cups fresh mushrooms, sliced (cremini or button mushrooms)
3 cups fresh spinach, roughly chopped
8 large eggs
½ cup milk (or dairy-free alternative)
1 cup shredded cheese (cheddar, mozzarella, or a blend)
1 teaspoon salt
½ teaspoon black pepper
½ teaspoon garlic powder
¼ teaspoon nutmeg (optional, enhances spinach flavor)
¼ cup chopped fresh parsley (optional for garnish)

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Instructions

Preheat and Prepare:
- Preheat your oven to 375°F (190°C).
- Grease a 9×13-inch baking dish with non-stick spray or a light coating of olive oil.
Sauté Vegetables:
- Heat olive oil in a large skillet over medium heat.
- Add chopped onions and sauté until they become translucent (about 3 minutes).
- Add mushrooms and cook until tender and slightly browned (about 5 minutes).
- Stir in spinach and cook until wilted. Remove from heat and set aside.
Whisk Eggs and Seasoning:
- In a large bowl, whisk together eggs, milk, salt, black pepper, garlic powder, and nutmeg.
- Stir in shredded cheese.
Combine and Assemble:
- Spread the sautéed vegetables evenly in the prepared baking dish.
- Pour the egg mixture over the vegetables.
- Use a spatula to distribute the ingredients evenly.
Bake:
- Place the casserole in the preheated oven.
- Bake for 25-30 minutes or until the eggs are fully set and the top is golden.
Serve and Garnish:
- Allow the casserole to cool slightly before cutting.
- Garnish with chopped parsley if desired.
- Serve warm.

Notes

Make-Ahead Option: You can assemble this casserole the night before and bake it the next morning.
Storage: Store leftovers in an airtight container in the refrigerator for up to 3 days.
Freezing: The baked casserole can be frozen for up to 2 months. Thaw overnight in the refrigerator before reheating.
Customization Tips: Feel free to add diced bell peppers, cooked bacon (or turkey bacon), or swap out the cheese for your favorite variety.
Dairy-Free Option: Use a plant-based milk and dairy-free cheese.

Author: Khadija
Prep Time: 15 minutes
Cook Time: 30 minutes
Category: Breakfast, Brunch, Main Dish
Method: Baking
Cuisine: American
Diet: Vegetarian

Nutrition

Serving Size: 1 slice (approx. 1/6 of the casserole)
Calories: 220
Sugar: 2g
Sodium: 420mg
Fat: 15g
Saturated Fat: 6g
Unsaturated Fat: 7g
Trans Fat: 0g
Carbohydrates: 5g
Fiber: 1g
Protein: 15g
Cholesterol: 210mg