Name: Healthy Breakfast Casserole With Vegetables
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Ingredients: 10 large eggs; 3/4 cup milk (dairy or unsweetened almond milk); 1 cup shredded cheese (cheddar, mozzarella, or pepper jack); 1 tablespoon olive oil (plus more for the pan); 1 small onion, diced; 1 red bell pepper, diced; 2 cups broccoli florets, chopped small; 2 cups baby spinach, roughly chopped; 1 small zucchini, diced (optional); 2 cloves garlic, minced; 1/2 teaspoon kosher salt, plus more to taste; 1/4 teaspoon black pepper; 1/2 teaspoon smoked paprika (or sweet paprika); 1/2 teaspoon dried oregano or Italian seasoning; Fresh herbs like parsley or chives for serving (optional); Optional protein add-ins: 1 cup cooked turkey sausage, chicken sausage, or black beans

This casserole is the kind of breakfast that makes your morning easier. It’s hearty without being heavy, loaded with colorful vegetables, and easy to adapt to what you have on hand. The texture is soft and custardy with lightly crisp edges, and it reheats like a dream.

You can build it the night before, bake it in the morning, and feed a crowd without standing at the stove. It’s reliable, wholesome, and genuinely delicious.

Why This Recipe Works

This recipe keeps things simple while delivering a lot of flavor. The base is eggs and a small amount of dairy for creaminess, balanced with a generous mix of sautéed vegetables.

Using a modest portion of cheese adds richness without overpowering the vegetables. Par-cooking the vegetables removes excess moisture, so the casserole sets well and doesn’t turn watery. A light sprinkle of herbs brightens the whole dish and makes the kitchen smell amazing.

Ingredients

10 large eggs
3/4 cup milk (dairy or unsweetened almond milk)
1 cup shredded cheese (cheddar, mozzarella, or pepper jack)
1 tablespoon olive oil (plus more for the pan)
1 small onion, diced
1 red bell pepper, diced
2 cups broccoli florets, chopped small
2 cups baby spinach, roughly chopped
1 small zucchini, diced (optional)
2 cloves garlic, minced
1/2 teaspoon kosher salt, plus more to taste
1/4 teaspoon black pepper
1/2 teaspoon smoked paprika (or sweet paprika)
1/2 teaspoon dried oregano or Italian seasoning
Fresh herbs like parsley or chives for serving (optional)
Optional protein add-ins: 1 cup cooked turkey sausage, chicken sausage, or black beans

How to Make Breakfast Casserole With Vegetables

Preheat and prep the pan. Heat the oven to 375°F (190°C).
Lightly oil a 9×13-inch baking dish and set it aside.
Sauté the vegetables. Warm the olive oil in a large skillet over medium heat. Add onion and bell pepper and cook until softened, about 4–5 minutes.
Add the broccoli and zucchini. Cook for another 3–4 minutes until the broccoli turns bright green and begins to soften. Stir in the garlic and cook for 30 seconds until fragrant.
Wilt the spinach. Add the spinach and cook just until wilted.
Remove the pan from heat. Season the vegetables with a pinch of salt and pepper. This step helps drive off moisture so the casserole bakes evenly.
Whisk the eggs. In a large bowl, whisk the eggs, milk, salt, pepper, paprika, and oregano until well combined.
Avoid over-whisking; you want it smooth but not frothy.
Layer the dish. Spread the sautéed vegetables evenly in the prepared baking dish. If using cooked sausage or beans, scatter them over the vegetables.
Add cheese and eggs. Sprinkle half the cheese over the vegetables. Pour the egg mixture over the top, then finish with the remaining cheese.
Bake. Place the dish on the center rack and bake for 28–35 minutes, or until the center is set and the edges are lightly golden.
A knife inserted near the center should come out mostly clean.
Rest and slice. Let the casserole rest for 5–10 minutes before slicing. This helps it set and makes clean squares.
Finish and serve. Top with chopped fresh herbs if you like. Serve warm with a side of fruit, avocado, or a simple green salad.

Keeping It Fresh

This casserole keeps well for busy mornings.

Let it cool completely, then store slices in airtight containers in the refrigerator for up to 4 days. Reheat in the microwave for 60–90 seconds, or in a 325°F (165°C) oven for 8–10 minutes for crisper edges.

For longer storage, freeze individual portions tightly wrapped for up to 2 months. Thaw overnight in the fridge and reheat as above.

Avoid freezing the whole casserole in the dish unless it’s freezer-safe and well wrapped to prevent freezer burn.

Easy breakfast casserole with vegetables

Benefits of This Recipe

Vegetable-forward: A generous amount of produce packs in fiber, vitamins, and color.
Protein-rich: Eggs provide complete protein to keep you full longer.
Make-ahead friendly: Assemble the night before and bake in the morning, or bake once and reheat.
Customizable: Swap vegetables, cheeses, or add lean proteins to suit your taste or what’s in the fridge.
Balanced: A good mix of protein, healthy fats, and complex carbs (if you pair it with whole-grain toast or roasted potatoes).

What Not to Do

Don’t skip pre-cooking watery vegetables. Raw mushrooms, zucchini, and tomatoes release moisture and can make the casserole soggy.
Don’t overbake. Overcooked eggs turn rubbery. Pull the casserole when the center is just set.
Don’t overload with cheese. Too much cheese can weigh it down and add excess grease.
Don’t use sweetened milk alternatives. They can make the casserole taste off. Stick to unsweetened.
Don’t forget to season the vegetables. Layering seasoning ensures the whole dish tastes balanced.

Alternatives

Dairy-free: Use unsweetened almond, cashew, or oat milk and swap cheese for a dairy-free shredded alternative, or skip cheese altogether and add an extra egg for structure.
Low-carb: Skip starchy add-ins and focus on leafy greens, mushrooms, peppers, and broccoli.
High-fiber: Add 1 cup of cooked quinoa or a can of drained, rinsed black beans to the vegetable layer.
Spicy: Use pepper jack cheese, add red pepper flakes, or stir in a diced jalapeño with the onions.
Mediterranean: Try feta instead of cheddar, add cherry tomatoes (seeded and sautéed), olives, and a pinch of dried thyme.
Meat lovers: Fold in lean turkey sausage, chicken sausage, or diced ham—just make sure it’s fully cooked and not too salty.
Herb-forward: Swap oregano for fresh dill, basil, or chives added after baking for brightness.

FAQ’s For Breakfast Casserole With Vegetables

Can I make this the night before?

Yes. Assemble everything in the baking dish, cover, and refrigerate overnight. In the morning, uncover and let it sit at room temperature for 15 minutes while the oven preheats, then bake as directed. You may need a couple extra minutes of bake time.

How do I prevent a watery casserole?

Sauté moisture-heavy vegetables first and let them cool slightly before adding to the dish. Avoid frozen vegetables unless you thaw and drain them well. Don’t add extra milk beyond what’s listed.

What size pan should I use?

A 9×13-inch dish works best. If you use an 8×8 or 9×9, reduce the recipe by about one-third or plan for a longer bake time because the casserole will be thicker.

Can I use egg whites only?

You can use a mix of whole eggs and egg whites. For a lighter version, try 6 whole eggs plus 1 1/2 cups egg whites. The texture will be slightly less rich but still satisfying.

What cheese works best?

Cheddar gives a classic flavor and nice melt. Mozzarella is mild and stretchy. Pepper jack adds heat. Feta brings a salty tang but doesn’t melt smoothly, so use it in combination with a melty cheese.

How long does it keep?

In the fridge, up to 4 days. Frozen, up to 2 months. Store in airtight containers to prevent drying out and off odors.

Can I add potatoes?

Yes. Par-cook diced potatoes or use thawed, drained hash browns. Sauté until just tender, then add to the vegetable layer. You may need a few extra minutes of bake time.

Is this good for meal prep?

Absolutely. Bake once, slice into squares, and store as individual portions. It reheats quickly and tastes just as good on day three as it does on day one.

Final Thoughts

This Healthy Breakfast Casserole with Vegetables is a dependable, flexible recipe that fits real life.

It’s easy to prep, tastes great warm or reheated, and keeps you full without feeling heavy. Keep the method the same, swap in the vegetables you love, and make it your own. With a little planning, breakfast becomes one less thing to worry about—and something to look forward to.