Breakfast Egg Casserole With No Bread

• Cooked vegetables manage moisture here. Browning sausage and softening pepper and onion before eggs arrive helps the casserole set with a cohesive, sliceable middle instead of wet edge pockets.
• Ten eggs and modest milk make enough custard for six squares without becoming loose scramble. Cheddar is divided so some melts through the center and the rest browns on top.
• With no bread to absorb liquid, resting the baked dish matters. The pause finishes the set and makes portions easier to lift, pack, and reheat.

• 1 tablespoon olive oil (14 g)
• 12 ounces chicken breakfast sausage, casings removed (340 g)
• 1 medium red bell pepper, finely diced (150 g)
• 1 small yellow onion, finely diced (110 g)
• 5 ounces baby spinach, roughly chopped (142 g)
• 10 large eggs (500 g)
• 1/2 cup whole milk (120 g)
• 1 teaspoon kosher salt (5 g)
• 1/2 teaspoon black pepper (1 g)
• 1 teaspoon garlic powder (3 g)
• 1 1/2 cups shredded cheddar cheese, divided (170 g)

Ingredient notes

• Chicken breakfast sausage brings seasoning and richness without a separate spice blend. Remove any casings before cooking, then break the meat into small crumbles so it distributes evenly through each slice. Pork breakfast sausage also works, though its seasoning and rendered fat can vary considerably by package.
• Use a red bell pepper for mild sweetness and clear color in the finished squares. Dice it quite small, about pea-size, so it softens in the same time as the onion and does not leave large watery pockets.
• Baby spinach is convenient because it wilts quickly, but it still needs time in the skillet for excess moisture to cook off. Roughly chop large leaves first; long strands can pull out of a cleanly cut portion.
• Whole milk gives the egg mixture a softer custard texture without making it thin. Use half-and-half for a richer result, or use an equal amount of unsweetened plain dairy-free milk if that is what is available.
• Shred cheddar from a block when possible for a smoother melt and less powdery coating. Monterey Jack, pepper Jack, Swiss, or a blend of cheddar and mozzarella can replace it; choose a cheese that melts rather than stays crumbly.

1. 1Heat oven

   Heat the oven to 350°F and oil a 9-by-13-inch baking dish. Set a large skillet over medium heat. Keep the dish nearby now; the cooked filling should move into it promptly, without lingering while the egg mixture waits.

2. 2Brown sausage

   Add olive oil, then crumble in the chicken sausage. Cook, stirring and breaking up larger pieces, until browned with no pink-looking centers. Transfer the sausage to a plate with a slotted spoon, leaving a little rendered fat in the skillet.

   

3. 3Soften vegetables

   Add bell pepper and onion to the skillet. Cook until the onion looks translucent and the pepper has softened, scraping up the browned bits. Add spinach by handfuls and stir until fully wilted. Keep cooking until the skillet looks dry rather than steamy.

   

4. 4Whisk custard

   Crack the eggs into a large bowl and whisk until the yolks and whites are fully blended. Whisk in milk, salt, pepper, and garlic powder. Stir in the cooked sausage, vegetables, and one cup of the cheddar until the filling is evenly mixed.

5. 5Fill dish

   Pour the egg mixture into the prepared dish and nudge the vegetables into an even layer with a spatula. Scatter the remaining cheddar across the top. This quick leveling step matters because the breadless filling has nothing underneath to disguise an uneven layer.

6. 6Bake and rest

   Bake until the center reaches 160°F and no longer looks liquid when the dish is gently moved, about 32 to 36 minutes. Rest the casserole for 10 minutes before cutting six squares. That rest gives the custard time to settle for cleaner portions.

• Use a 9-by-13-inch metal or ceramic baking dish. Extra depth delays the center, so edges can overcook before the middle reaches 160°F.
• Cook spinach until the skillet looks nearly dry. Excess vegetable moisture is the usual cause of a watery layer beneath the rested eggs.
• Whisk only until yolks and whites blend with milk and seasonings. Foam can create an uneven, puffy texture that collapses as the casserole cools.
• Begin checking at 32 minutes with an instant-read thermometer in center. Stop at 160°F; a gentle overall jiggle is acceptable because carryover heat finishes setting during rest.
• Loosen perimeter with a thin spatula after the ten-minute rest, then cut cleanly. Let the first square be the cook’s portion, because remaining pieces lift more neatly.

Serve a warm square with berries, orange segments, or a simple side of sliced tomatoes for a breakfast that does not require much assembly. A spoonful of salsa, hot sauce, or chopped herbs works well at the table. For a more filling plate, add roasted potatoes alongside rather than inside the casserole; keeping them separate preserves the clean egg texture. It also fits easily into a container with fruit for a desk breakfast.