Grease a 9x13 baking dish.
In a large saucepan, cook onion, garlic and bell peppers in oil over medium heat until tender, about 5 minutes. Stir in sausage.
Place ¼ cup of sausage mixture and 3 tablespoons of cheese on the end of a tortilla. Roll up and place seam side down in prepared pan. Repeat with remaining tortillas.
Whisk eggs, milk, flour, oregano, hot sauce, salt and pepper to taste. Pour over tortillas. Cover with foil and refrigerate overnight.
Preheat oven to 350°F. Remove pan from fridge while the oven preheats, about 20 minutes.
Bake covered for 35 minutes. Remove foil and top with remaining cheese. Bake an additional 15-20 minutes or until eggs are set. Serve with sour cream, salsa and toppings as desired.