To make the marinade: in a food processor, combine the scallions, garlic and ginger and pulse to chop finely. Add the cilantro, oil, juice and soy sauce and puree.
Transfer the marinade to a medium non-reactive bowl and add the chicken. Stir to coat and marinate. Refrigerate 2 hours or overnight.
To make the peanut sauce: in a food processor, combine the scallions, garlic, ginger and cilantro and pulse to chop finely. Add the peanut butter, coconut milk, lime juice, soy sauce and chili paste and process to blend. Add more coconut milk if the sauce is too thick.
Set up a grill or preheat a grill pan. Thread each chicken piece on a skewer. Grill, turning once, until the chicken is just cooked through, about 1-1/2 minutes per side. Serve with peanut sauce.
Ingredients:
Ingredients for the marinade:
Ingredients for peanut sauce: