Moo Shu Beef Lettuce Cups

1. Coat a large non-stick skillet with cooking spray and set pan over medium-high heat. 2. Add beef, onion, ginger and garlic; cook until beef is browned and onion is soft, breaking up meat as it cooks, about 5 to 7 minutes. 3. Add bok choy, pepper, mushrooms, and soy sauce; cook, stirring occasionally, until bok choy is wilted and pepper is tender-crisp, about 3 to 5 minutes. 4. Spoon about 1/2 cup of beef mixture into each lettuce leaf. 5. Note: to serve 4, increase quantities to 1 lb beef; 1 cup chopped onion; 2 tbsp ginger; 2 tbsp garlic, 1 cup bok choy; 1 bell pepper; 2 tbsp soy sauce and 8 lettuce leaves.