The pan sauce can be reduced a bit before serving.
Preheat oven to 375
Mix the 2.5 cup sauce and beef broth in a baking dish. Sprinkle onions over top.
Combine the beef, rice, cheese, parsley, 2nd sauce, garlic, salt, and pepper.
Poke a few drainage holes in each pepper and stuff with meat combination. NOTE: slicing a thin slice off the bottom of the pepper may help them stand. Place the peppers in the baking dish with the sauce. Tightly cover with tin foil and place in oven about 1 hour. Remove foil and continue to bake until meat is done and peppers tender. Baste with pan sauce from time to time after removing the foil.