Add the sesame oil to a large skillet set over medium heat.
2 teaspoons toasted sesame oil
When the sesame oil is fragrant, add the ground chicken and sauté, breaking up the chicken, until it is cooked through and no longer pink, about 5-7 minutes.
1 pound ground chicken
Add the onion, garlic, and ginger. Sauté for an additional 3-4 minutes or until the onions are soft.
¼ cup finely diced onion, 2 teaspoons freshly minced garlic, 1 teaspoon grated fresh ginger
Add the sauce to the pan and stir until the chicken is evenly coated. Cook for another minute. If the sauce thickens too quickly, thin it with ¼ cup water.
Add the water chestnuts and green onions. Toss to combine and remove from the heat.
8 ounces water chestnuts, ¼ cup thinly sliced green onions
Fill each piece of butter lettuce with a spoonful of the chicken mixture and serve.
1 head butter lettuce