In a large skillet, heat sesame oil over medium heat.
Add ground chicken, garlic, and ginger. Cook until chicken is browned, about 5-6 minutes.
Stir in hoisin sauce, soy sauce, rice vinegar, and sriracha. Mix well.
Add chopped water chestnuts and green onions. Cook for another 2-3 minutes until heated through.
Spoon mixture into lettuce leaves and serve immediately.