1 (1-lb.) breakfast sausage roll
½ onion, diced
1 tablespoon unsalted butter
4 everything-seasoned bagels, torn into 1-inch pieces
8 ounces cream cheese, softened
1 cup whole milk
4-6 large eggs, as desired for more or less “eggy” texture
1 tablespoon hot sauce
1 teaspoon kosher salt
1/4 teaspoon black pepper
6 scallions, thinly sliced, white and light green parts separated from dark green parts, divided
8 ounces sharp white Cheddar cheese, shredded (about 2 cups), divided
1 tablespoon everything bagel seasoning
Preheat oven to 375°F.
Cook the sausage in a large skillet over medium-high, stirring often and breaking the meat up, until it’s nearly cooked through, ~5 minutes.
Add the onions and sauté until they’re nearly translucent.
Using a slotted spoon, transfer the sausage & onions to a 13 x 9-inch baking dish. Do not wipe the skillet clean.
Add the butter to the drippings in the skillet, and melt over medium.
Add the bagel pieces, then cook, tossing often, until they're coated and lightly toasted, about 3 minutes.
Add the bagel pieces and sausage mixture to a baking dish & set aside.
Place the cream cheese in a large bowl, and slowly whisk in milk until it’s combined. Add the eggs, hot sauce, salt, pepper, white and light green parts of scallions, and 3/4 of the cheese; whisk until combined.
Pour over the bagel mixture in the baking dish; toss lightly to evenly distribute all of the ingredients.
Let the casserole stand at room temperature 30 minutes to allow the bread to absorb the liquid.
Sprinkle evenly with the remaining cheese.
Bake uncovered, in preheated oven until the eggs are set and the top of casserole is golden brown, about 30 minutes.
Sprinkle the casserole with everything bagel seasoning and the dark green parts of the scallions.
Let stand 10 minutes. Serve.
Overnight/Make-Ahead option: Assemble casserole as directed in Steps 1 and 2. Cover assembled casserole, and refrigerate overnight. Preheat oven to 375°F; remove casserole from refrigerator, and let stand, uncovered, at room temperature while oven preheats. Bake as directed in Step 3, adding 5 to 6 minutes to bake time, if needed.