In a large skillet set over medium heat, crumble the breakfast sausage and cook until browned and no longer pink, about 6-8 minutes. Remove from heat and set aside.
In a mixing bowl, whisk together the eggs and milk until well combined. Add garlic powder, smoked paprika, and a generous amount of salt and pepper. Stir until fully incorporated.
Grease a 9x13 inch baking dish. Place half of the frozen tater tots evenly across the bottom.
Scatter the cooked sausage over the tater tots, then add the diced bell peppers and onions evenly.
Pour the egg mixture over the sausage and vegetable layers, ensuring everything is coated evenly.
Top with the remaining tater tots and sprinkle shredded cheddar cheese over the top.
Bake in the preheated oven for 45-50 minutes until the cheese is bubbly and golden brown.
Allow the casserole to cool for a few minutes before slicing into squares. Garnish with fresh chives if desired.