In a large skillet, cook ground beef and onion over medium heat until the meat is no longer pink; drain.
In a small bowl, combine the chili sauce, garlic, salt and chili powder; add to meat mixture. Stir in the rice, beans and chilies. Cover and cook over medium until heated through. Add tomato; cook 5 minutes longer.
For each serving, spoon 1 cup meat mixture over lettuce and sprinkle with cheese.