Heat 1 tablespoon of sesame oil in a large skillet over medium heat.
Add the onion and cook for 3 to 4 minutes until softened.
Stir in the garlic and ginger and cook for 30 seconds until fragrant.
Add the ground chicken and cook for 6 to 8 minutes, breaking it apart until fully cooked.
In a small bowl, whisk together the soy sauce, hoisin sauce, rice vinegar, honey, and 1 teaspoon sesame oil.
Pour the sauce into the skillet and stir to coat the chicken.
Mix the cornstarch with the water, then stir it into the skillet. Cook for 2 to 3 minutes until the sauce thickens.
Stir in the sliced green onions.
Spoon the chicken mixture into the lettuce leaves.
Garnish with cilantro and sesame seeds before serving.