In a large bowl, combine the garlic, ginger, rice vinegar, soy sauce, brown sugar, peanut butter and sesame oil. Set the marinade aside.
Slice the chicken breasts into long, thin strips. Add the chicken strips to the marinade and mix well. Refrigerate 1 hour or for up to overnight.
When ready to cook, preheat the grill - high heat on one side and low heat on the other side. Thread the chicken strips onto the bamboo skewers, keeping the chicken as flat as you can so that they cook evenly. Grill the chicken skewers, starting on the high heat side for 4 minutes each side. The move the skewers to the low heat side, cover and finish cooking, about 1-3 minutes more, depending on the thickness of your chicken.
Serve with chopped roasted peanuts sprinkled on top.