Preheat your oven to 375°F (190°C). Lightly grease a 9 x 13 inch baking dish.
Heat 2 tbsp of oil in a large skillet over medium-high heat. Add beef and sausage, breaking them up, and cook for 6–8 minutes until browned.
Add chopped onion and green bell pepper to the skillet, cooking for 4–5 minutes until softened. Add garlic and cook for an additional 30–60 seconds.
Stir in chili powder, smoked paprika, cumin, oregano, salt, black pepper, and crushed red pepper flakes. Cook for 1 minute.
Add baked beans, kidney beans, pinto beans, diced tomatoes, and corn to the skillet. Mix well.
In a bowl, combine cream of mushroom soup, beef broth, barbecue sauce, tomato paste, Worcestershire sauce, and mustard. Mix until smooth.
Pour the sauce into the skillet and stir until everything is well coated. Let simmer for 5–7 minutes.
Pour the mixture into the prepared baking dish, spreading evenly. Top with shredded cheeses.
Arrange biscuit dough or tater tots over the cheese.
Bake the casserole for 25–35 minutes, until the toppings are golden and filling is bubbling.
Remove from the oven and let rest for 10–15 minutes before serving.
Serve with garnishes like sour cream, green onions, and jalapeños.
Notes
For a vegetarian option, substitute meat with beans and vegetables. Leftovers can be stored for up to 3 days and can be frozen for up to 3 months.