Brown the Meats & Aromatics: Preheat oven to 375°F (190°C). Grease a 9x13-inch ceramic baking dish with cooking spray or butter. In a large skillet over medium-high heat, cook ground sausage and diced onion, breaking into small crumbles until browned (5-6 mins). Add diced red bell pepper and minced garlic; sauté 2 more minutes. Drain excess grease and transfer mixture evenly into the prepared baking dish.

Whisk the Fluffy Egg Custard: In a large mixing bowl, vigorously whisk together the 8 eggs, milk, smoked paprika, garlic powder, onion powder, kosher salt, and black pepper until completely smooth and lightly frothy.

Layer Cheese & Eggs: Sprinkle 1 1/2 cups of the mixed cheeses and the crumbled bacon evenly over the sausage and vegetable layer in the dish. Pour the seasoned egg custard evenly over the entire dish, ensuring it settles between the meat and cheese.

Arrange the Tater Tots: Arrange frozen tater tots in neat, tight parallel rows directly across the top surface of the casserole, covering the entire dish from edge to edge.

Bake to Golden Perfection: Bake uncovered at 375°F (190°C) for 35 to 40 minutes, until the egg custard is fully set in the center and tots begin to turn golden. Remove from oven, sprinkle remaining 1 1/2 cups of cheese across the tots, and bake for an additional 8 to 10 minutes until cheese is melted and vigorously bubbling.

Rest, Garnish & Slice: Let the casserole rest for 10 minutes to allow the eggs to settle for clean slicing. Scatter fresh sliced scallions on top, slice into hearty squares, and serve hot with hot sauce!