Cheesy Sausage and Potato Breakfast Casserole

Ingredients (9)

• + 1 ½ pounds potatoes, peeled add to pantry
• ✓ cooking spray
• + 1 (16 ounce) package pork breakfast sausage add to pantry
• + 1 sweet onion, chopped add to pantry
• ✓ 7 eggs
• + 1 (8 ounce) package Cheddar cheese, grated, divided add to pantry
• ✓ ½ cup milk
• + salt and ground black pepper to taste add to pantry
• + salt and ground black pepper to taste add to pantry