1-First, preheat your oven to 350 degrees Fahrenheit and grease a 9×13-inch pan with cooking spray. In a large bowl, combine the 12 eggs, 1 cup sour cream, 1/4 cup milk, 2 cups shredded cheddar cheese, 1 teaspoon salt, and 1/2 teaspoon ground black pepper. Mix on low speed until just combined to create a smooth base.

2-Next, cook the 2 pounds sausage in a large skillet over medium heat, breaking it into small pieces until browned. Drain any excess grease and add the sausage to the egg mixture for added flavor and protein. In the same skillet, sauté the 1/2 green bell pepper (diced), 1/2 red bell pepper (diced), and 4 green onions for 2-3 minutes until they soften.

3-Add these sautéed veggies to the egg mixture and stir everything together thoroughly. Pour the entire mixture into your prepared pan and bake for 35-50 minutes, or until the edges set and the center is slightly jiggly. Let the casserole cool before serving, and store leftovers in the fridge for 3-4 days to reheat later.