In a small bowl whisk the peanut oil, garlic cloves, cumin, turmeric, soy sauce, fish sauce, and coconut milk together.
Arrange the chicken in a baking dish in one single layer and pour the marinade on top. Cover and refrigerate for a minimum of 30 minutes or up to 12 hours.
In a small saucepan over medium heat whisk all the peanut sauce ingredients together. Bring to a low simmer, stirring continuously, and cook for 3 minutes. Remove from heat and set aside.
Drain the chicken from the marinade, discarding the marinade.
Preheat the grill to medium-high heat or place a grill pan over medium-high heat.
Thread chicken onto skewers and brush with peanut oil; season with salt and pepper, to taste.
Add skewers to grill, and cook, turning occasionally, until the chicken is completely cooked through, reaching an internal temperature of 165ºF, about 12-15 minutes. If using a grill pan cook each skewer for 4 to 5 minutes on each side.
Serve with peanut sauce.