Prepare Lettuce: Wash, dry, and separate the lettuce leaves. Keep them chilled for extra crunch.
Cook Beef: Heat oil in a skillet over medium-high heat. Add garlic and ginger. Stir-fry for 30 seconds. Add ground beef and cook until browned.
Add Sauces: Stir in soy sauce, hoisin sauce, oyster sauce (if using), and sesame oil. Mix well so the beef absorbs all the flavors.
Mix Vegetables: Add carrots, water chestnuts, and green onions. Stir-fry for 2–3 minutes until slightly tender but still crisp. Add chili flakes or sriracha if you want it spicy.
Assemble Wraps: Spoon the beef mixture into lettuce leaves. Top with sesame seeds and extra green onions. Serve immediately.