Cheesy Sausage and Potato Breakfast Casserole

Step 1
Preheat an oven to 450 degrees F (230 degrees C). Prick potatoes several times with a fork and place onto a baking sheet.

Step 2
Bake in the preheated oven until potatoes are soft, 50 minutes to 1 hour. Remove potatoes from oven and let cool until safe to handle, at least 15 minutes.

Step 3
Reduce oven temperature to 350 degrees F (175 degrees C). Spray a casserole dish or 9×13-inch pan with cooking spray.

Step 4
Heat a large skillet over medium-high heat. Cook and stir sausage in the hot skillet until browned and crumbly, 5 to 7 minutes. Transfer sausage to a bowl. Saute onion in the same skillet until translucent, about 5 minutes. Transfer onion to the bowl with the cooked sausage.

Step 5
Mix eggs, half the Cheddar cheese, milk, salt, and pepper into the bowl with the sausage mixture.

Step 6
Grate potatoes and add to the bowl of sausage mixture. Pour mixture into the prepared dish; place remaining Cheddar cheese on top.

Step 7
Bake in the preheated oven until casserole is heated through and cheese is melted and bubbly, about 35 minutes.