This is one of my favorite recipes! I love all the flavor and crunch against the crispy lettuce cups.
In a large saute pan, heat 2 TBS of the oil in the saute pan over medium-high heat and cook the ground chicken, breaking it up with a wooden spoon, until cooked through. Season with salt and pepper and transfer to a bowl.
Add the remaining 2 TBS of the oil in the saute pan over medium heat and when hot, cook the garlic and ginger for about 1 minute, stirring to prevent burning. Add the pepper and cook for 1 to 2 minutes longer or until the pepper softens. Return the chicken to the pan and stir in the chestnuts to mix all the ingredients.
In a small cup, whisk the soy sauce and hoisin with 1/4 cup of water. Pour into the pan, add the scallions, and simmer for 1 minute, stirring to mix.
Remove the chicken from the heat and spoon the mixture into the Bibb lettuce leaves, which should cup the chicken. Garnish with sprigs of mint and cilantro as desired.