Why You’ll Love Vegetable Egg Casserole Recipe

This casserole is filled with colorful vegetables and protein-rich eggs, making it both nutritious and satisfying. It’s easy to prepare ahead of time, feeds a crowd, and can be customized with your favorite veggies or cheeses.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

2 tablespoons extra‑virgin olive oil, divided
16 oz mushrooms, sliced
Salt and freshly ground black pepper, to taste
2 bell peppers (any color), seeded and chopped
1 yellow or white onion, chopped
12 large eggs
1/2 cup milk (any kind)
30 oz frozen shredded hash browns, thawed
12 oz shredded mozzarella cheese, divided
12 oz shredded cheddar cheese, divided

Directions

Preheat the oven to 350°F (180°C). Lightly grease an 11×17‑inch baking dish or two medium baking dishes with nonstick spray.

Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the mushrooms and sauté until their liquid has evaporated and they turn golden. Season with salt and pepper, then transfer to a bowl and set aside.

Add the remaining olive oil to the skillet. Add the chopped bell peppers and onion, season with salt and pepper, and sauté until crisp‑tender. Spread the vegetables on a plate and let cool slightly.

In a large bowl, whisk together the eggs, milk, salt, and pepper. Add the hash browns, 8 oz of mozzarella, and 8 oz of cheddar to the egg mixture and stir until combined. Fold in the sautéed mushrooms, peppers, and onions.

Pour the mixture into the prepared baking dish. Sprinkle the remaining cheeses evenly over the top, cover loosely with foil, and bake for 50–60 minutes, or until the center is set. Remove the foil and bake 2–3 minutes more to fully melt the cheese. Let the casserole rest for 10 minutes before slicing and serving.

Servings and timing

Servings: 12
Prep time: about 30 minutes
Cook time: about 1 hour

Variations

Swap mozzarella or cheddar for Monterey Jack, Swiss, or your favorite cheese.

Add extra vegetables like spinach, zucchini, or broccoli for added nutrition.

Use dairy‑free milk and cheese to make this casserole suitable for dairy‑free diets.

Storage/Reheating

Store leftover casserole in an airtight container in the refrigerator for up to 4 days. Reheat portions in the microwave or in a 350°F (180°C) oven until warmed through. You can also freeze fully baked and cooled slices in freezer‑safe containers for up to 3 months; thaw in the fridge before reheating.

FAQs

How do I know when the casserole is done?

The center should be firm and no longer jiggle when you gently shake the baking dish.

Can I make this casserole ahead of time?

Yes — you can assemble the casserole, refrigerate uncovered or covered overnight, and bake when ready.

Can I add other vegetables?

Absolutely. Spinach, zucchini, broccoli, or tomatoes all work well once sautéed or prepped as needed.

Can this recipe be made dairy‑free?

Yes — substitute dairy‑free milk and cheese alternatives.

Can I halve the recipe?

Yes — you can halve the ingredients and bake in a smaller dish; reduce baking time slightly and check for doneness.

Is this recipe suitable for meal prep?

Yes — it reheats well and can be made ahead, making it excellent for meal prepping breakfasts.

Can I freeze this casserole?

Yes — freeze cooked and cooled portions. Thaw in the fridge before reheating.

Can I add meat to this casserole?

Yes — cooked bacon, sausage, or ham can be added for extra protein if you like.

What size baking dish should I use?

An 11×17‑inch baking dish works great for this recipe; smaller deep dishes can also be used.

Can I make it gluten‑free?

Yes — this vegetable egg casserole has no gluten ingredients unless you add something that contains gluten.

Conclusion

This Vegetable Egg Casserole is a versatile, flavorful dish that’s perfect for breakfast, brunch, or even dinner. With a colorful mix of vegetables, cheesy egg goodness, and ease of preparation, it’s sure to become a favorite in your recipe rotation.