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Chicken Spinach & Cheese Breakfast Casserole

When you want a breakfast that feels comforting, filling, and easy enough for a busy morning, this Chicken Spinach & Cheese Breakfast Casserole is a wonderful choice. It combines tender seasoned chicken, fresh spinach, fluffy eggs, and plenty of melted cheese in one hearty baked dish.

The casserole can be prepared ahead of time, making it especially useful for weekends, family breakfasts, brunch gatherings, or meal prep. As it bakes, the eggs become light and tender while the cheese melts into every layer, creating a golden, savory top.

Why You’ll Love This Breakfast Casserole

This recipe is more than just an easy way to use leftover chicken. The combination of protein-rich chicken and eggs with spinach and cheese makes it satisfying without requiring complicated preparation.

It is also flexible. You can use leftover roasted chicken, shredded rotisserie chicken, or freshly cooked chicken breast. Different cheeses can be substituted depending on what you have available, and the spinach can easily be combined with other vegetables.

Most importantly, everything comes together in one baking dish, so cleanup is simple.

Ingredients

2 cups cooked chicken, shredded or diced
6 large eggs
1 cup milk
2 cups fresh spinach
1 cup shredded cheddar cheese
½ cup shredded mozzarella cheese
½ small onion, finely diced
1 tablespoon olive oil or butter
½ teaspoon garlic powder
½ teaspoon paprika
½ teaspoon salt
¼ teaspoon black pepper
3 cups cubed day-old bread
2 tablespoons chopped fresh parsley, optional

Step 1: Prepare the Chicken

If you are using leftover cooked chicken, simply shred or chop it into bite-sized pieces.

For freshly cooked chicken, season it lightly with salt, pepper, and a little paprika before cooking until completely done. Allow it to cool slightly, then shred or dice it.

Using bite-sized pieces helps distribute the chicken throughout the casserole instead of leaving large pieces concentrated in one area.

Step 2: Sauté the Onion and Spinach

Preheat your oven to 375°F (190°C).

Heat the olive oil or butter in a skillet over medium heat. Add the diced onion and cook for about 3–4 minutes, stirring occasionally, until it begins to soften.

Add the fresh spinach and cook for another 1–2 minutes. The spinach will quickly wilt and become much smaller in volume.

Remove the skillet from the heat and let the mixture cool for a few minutes.

A useful tip

If the spinach releases a lot of moisture, allow it to cook for another minute or two so excess liquid evaporates. This helps prevent the finished casserole from becoming watery.