Cut the bell peppers in half, top to bottom. Remove the seeds and the ribs. Set aside. In a medium saucepan, cook the rice according to package directions. In a medium skillet, brown the ground beef, onion, and garlic. Drain the meat. In a medium saucepan, bring the tomatoes to a boil, then reduce the heat and simmer for 5 minutes. Remove from the heat. In a large bowl, combine the ground beef, rice, tomatoes, pepper, and salt and mix until blended.