Heat the oil in a large skillet over medium-high. Add in the chicken, and cook, stirring and breaking up the pieces until cooked through.
Add in the onion, bell pepper, garlic, cayenne pepper, cumin and ginger.
Stir, and cook for about 4 minutes, or until onion is soft.
Add the water chestnuts, green onions, soy sauce, honey, rice vinegar, sea salt and pepper to taste, and cook for about 3 minutes, until the sauce has thickened.
Spoon about 1/4 cup of the mixture into the butter lettuce leaves to serve.