Make the satay: In a medium bowl, mix the yogurt with the curry powder, cumin, coriander and cayenne to combine. Add the chicken and toss the meat in the marinade. Marinate, covered and refrigerated, for 1 hour (and up to overnight).
Make the sauce: In a blender or food processor, puree the peanut butter with the coconut milk, soy sauce, rice wine vinegar, garlic, ginger and chile paste until smooth. Transfer to a bowl and garnish with peanuts.
Cook the satay: Heat a grill, grill pan or large skillet over high heat. While it’s heating up, thread the marinated chicken onto the skewers. Place the chicken skewers onto the hot cooking surface and cook until nicely charred on both sides, 3 to 5 minutes per side.
To serve, place the chicken skewers on a plate with a portion of the peanut sauce. Garnish with chopped fresh cilantro or sliced scallions, if desired.