Step 1: Preheat and Prepare

1. Preheat the oven to 350°F.
2. Grease a 9″x13″ casserole dish and set aside.

Step 2: Cook the Bacon

1. In a large skillet over medium heat, cook the chopped bacon until crispy.
2. Remove bacon with a slotted spoon and place it on a plate lined with paper towels to drain.

Step 3: Assemble the Casserole

1. Arrange the frozen tater tots in an even layer in the prepared casserole dish.
2. Sprinkle half of the cooked bacon over the tater tots.

Step 4: Prepare the Egg Mixture

1. In a large mixing bowl, whisk together the eggs, Colby Jack cheese, milk, half of the green onions, salt, and black pepper.
2. Pour the egg mixture evenly over the tater tots and bacon in the casserole dish.

Step 5: Bake the Casserole

1. Bake in the preheated oven for 30 minutes.
2. After 30 minutes, remove the casserole from the oven and sprinkle the shredded cheddar cheese, remaining bacon, and remaining green onions over the top.
3. Return to the oven and bake for an additional 20-30 minutes, or until the eggs are fully set and the cheese is melted.

Step 6: Make the Sausage Gravy

1. While the casserole bakes, heat a large skillet over medium heat. Add the ground sausage and cook until browned and fully cooked, breaking it into crumbles.
2. Sprinkle the flour over the sausage and stir to combine. Let it cook for 2 minutes to eliminate the raw flour taste.
3. Gradually add the milk, about ½ cup at a time, whisking constantly to prevent lumps. Continue adding milk until the gravy reaches your desired consistency (approximately 3 cups).
4. Simmer the gravy until thickened, then season with white pepper, salt, and black pepper to taste.

Step 7: Serve and Enjoy

1. Remove the casserole from the oven and let it cool for 5 minutes before slicing.
2. Serve individual portions topped with warm sausage gravy.