High-Protein Chicken Spinach Breakfast Casserole with Feta
A protein-packed breakfast casserole featuring tender chicken, wilted spinach, and tangy sun-dried tomatoes bound together with eggs and creamy feta cheese. This hearty dish serves a crowd and works perfectly for meal prep, holiday brunches, or busy weekday mornings when you need something substantial. The combination of whole eggs and egg whites keeps it lighter while maintaining rich flavor, and the Mediterranean-inspired ingredients add complexity beyond typical breakfast fare.
Ingredients
Instructions
- 1
Preheat oven to 375 degrees Fahrenheit and spray a 13x9 inch casserole dish with cooking spray
- 2
Heat avocado oil in a large skillet over medium-high heat
- 3
Add chopped onion and sauté until softened, about 5 to 8 minutes
- 4
Add garlic and spinach, cover until spinach wilts, about 2 minutes
- 5
Stir in sun-dried tomatoes and season with salt, then remove from heat
- 6
Transfer chicken and vegetable mixture to prepared casserole dish and spread evenly
- 7
Whisk eggs and egg whites together in a large bowl until well combined
- 8
Pour egg mixture evenly over chicken and vegetables
- 9
Stir in feta cheese and distribute ingredients throughout casserole
- 10
Bake for 35 to 45 minutes until golden brown and center tests clean
- 11
Cool for at least 10 minutes before slicing and serving
Tips
Use rotisserie chicken for convenience, or cook chicken breasts seasoned with salt and pepper until internal temperature reaches 165°F
Squeeze excess water from spinach after wilting to prevent a watery casserole
Make ahead by assembling the night before and refrigerating, then bake in the morning adding 5-10 minutes to cook time
Good to Know
Refrigerate covered for up to 3 days
Assemble up to 24 hours ahead, cover and refrigerate, then bake adding 5-10 minutes
Serve warm with Greek yogurt, sour cream, or fresh fruit
Common Mistakes
Drain sun-dried tomatoes well to avoid excess oil
Squeeze wilted spinach to remove water and prevent soggy casserole
Let cool 10 minutes before cutting to allow setting
Substitutions
FAQ
Can I freeze this casserole?
Yes, freeze baked casserole up to 3 months. Thaw overnight in refrigerator and reheat at 350°F for 20-25 minutes until heated through.
What if I don't have egg whites?
Use 3 additional whole eggs instead of the carton of egg whites, though the casserole will be slightly richer and higher in calories.
How long will leftovers keep?
Store covered in refrigerator for up to 3 days. Reheat individual portions in microwave for 1-2 minutes or in 350°F oven for 10 minutes.