This hearty frittata packs savory sausage, tender spinach, and melty cheese into a golden, oven-baked breakfast. It’s simple, satisfying, and perfect for any time of day.
Heat the oven to 375°F and place a rack in the center.
Warm olive oil and butter in a 10-inch oven-safe skillet over medium heat.
Brown the sausage, breaking it up with a spoon, until no longer pink. Spoon off excess fat.
Stir in onion and cook until translucent, 3–4 minutes. Add garlic and cook 30 seconds.
Fold in spinach and cook until wilted. Spread the mixture in an even layer.
Whisk eggs with milk, salt, pepper, and red pepper flakes. Stir in half the cheddar.
Pour the egg mixture over the skillet fillings. Gently stir, then top with remaining cheddar and Parmesan.
Cook without stirring until the edges just begin to set, about 2 minutes.
Bake until the center is barely set and the top is lightly golden, 10–12 minutes. Rest 5 minutes before slicing.
Notes
Try swapping cheddar for smoked gouda or pepper jack for a spicier twist. For meal prep, chill slices in an airtight container up to 4 days; reheat gently in a skillet or microwave. To make it vegetarian, substitute sautéed mushrooms for the sausage and add a pinch more salt.This recipe is an original creation inspired by classic Sausage Spinach Cheese Frittata Recipe flavors. All ingredient ratios and instructions are independently developed.