Carefully remove piece from the lettuce head, maintaining their cup shape as much as possible. Wash well and pat dry with paper towels. Return to the fridge to keep crisp.
Prep your ingredients: mince the garlic, grate the ginger, and dice the water chestnuts.
In a large pan, add 1 tablespoon olive oil and garlic over medium high heat. After about 1 min, add ground chicken. Stir and cook the chicken, breaking apart into smaller pieces. Once the chicken is mostly cooked, add soy sauce, ponzu, ginger, hoisin, and Sambal Oelek. Stir well to incorporate.
When the chicken is fully cooked and coated well in the sauce, add water chestnut and mix well. Stir and cook for an additional 1-2 minutes, then remove from heat.
Serve alongside the lettuce cups with chopped cilantro, sesame seeds, hoisin sauce, soy, and Sambal Oelek.