In a medium bowl combine together peanut butter, soy sauce, vinegar, fish sauce, garlic and ginger. Whisk until smooth. Reserve 1/2 cup of sauce.
Place chicken and remaining sauce in a resealable bag. Gently massage chicken with sauce in the resealable bag. Refrigerate for 30-60 minutes to marinate.
Grill over high heat until cooked through (165F).
Serve with reserved sauce as a dip.
Chef's Tip!
Use the Thai peanut sauce on portabella mushrooms for a vegetarian twist.