If baking immediately, preheat the oven to 350 degrees F.

In a large frying pan, over medium heat, cook the breakfast sausage until no pink remains. Break into small pieces.

Grease a 9x13-inch pan with cooking spray. Place the tater tots in a single layer across the bottom of the pan.

Dice the red pepper and chop the green onions. Set aside.

In a medium bowl, whisk together the eggs, milk, sour cream, salt, and pepper until thoroughly combined.

Sprinkle the breakfast sausage evenly over the tater tots. Followed by the diced red pepper, green onions, and half of the shredded cheese.

Pour the egg mixture over tater tots, sausage, and peppers in the pan.

If wanted, cook the egg casserole immediately in a preheated 350 degree F oven. Follow the cooking instructions below.

To bake later, cover and refrigerate overnight - up to 18 hours.

Preheat the oven to 350 degrees F. Bake covered for 30 minutes. Uncover and add the remaining shredded cheese. Bake for an additional 15 minutes or until no longer jiggly. Serve warm. Garnish with chopped green onions, salsa, sour cream, or hot sauce if wanted.