Cut tops off peppers and remove seeds.
In a Dutch oven, cook peppers in boiling water for 3-5 minutes.
Drain and rinse in cold water; set aside.
Cook orzo according to package directions.
Meanwhile, in a large skillet, cook sausage and onion over medium heat until meat is no longer pink.
Add garlic; cook 1 minute longer. Drain.
Drain orzo; stir into meat mixture.
Add the marinara sauce, tomato, basil, rosemary and pepper flakes.
Spoon into peppers.
Place in a greased 11x7-in. baking dish.
Cover and bake at 350° for 10 minutes.
Uncover; sprinkle with cheeses.
Bake 5 minutes longer or until cheese is melted.
