Heat oil in wok or large skillet over medium-high heat. Add garlic; stir-fry until browned, 20 to 30 seconds. Add beef and stir-fry until browned. Add ginger, fish sauce, and soy sauce; stir-fry for 1 minute. Mix in oyster sauce and sugar. Add bell pepper and onion. Cover, remove from heat and let stand for 2 minutes. Serve hot over freshly-cooked rice. Bon Appetit's LIGHT AND EASY SPECIAL EDITION