In a large skillet over medium heat, cook the ground breakfast sausage until browned, about 5–7 minutes. Drain any excess grease and set aside.

Preheat your oven to 350°F (175°C). Grease a 9x13-inch casserole dish.

In a mixing bowl, combine the cooked rice, sausage mixture, cream of mushroom soup, sour cream, garlic powder, onion powder, and half of the shredded cheese. Stir until well incorporated.

Spread the mixture evenly in the greased casserole dish. Top with the remaining cheese.

Cover with foil and bake for 25 minutes, then uncovered for an additional 10–15 minutes until the cheese is golden and bubbly.

Let cool for about 5 minutes before garnishing with diced red bell peppers.