Make the Marinade: In a medium bowl, whisk together peanut butter, soy sauce, coconut milk, lime juice, honey, fish sauce, brown sugar, coriander, cumin, turmeric, cayenne pepper, garlic, and ginger until smooth.
Marinate the Chicken: Add chicken cubes to the marinade, ensuring they are fully coated. Cover and refrigerate for at least 30 minutes, or up to overnight.
Prepare the Sauce: Reserve 1/3 cup of the marinade for the satay sauce.
Thread Skewers: If using wooden skewers, soak them in water for 30 minutes. Thread marinated chicken onto skewers, leaving a small space between pieces.
Grill Chicken: Preheat grill to medium-high heat. Grill skewers for 5-7 minutes per side, until chicken is cooked through to 165°F (74°C) and has grill marks.
Make Satay Sauce: In a small pot, combine reserved marinade with 1/4 cup water. Heat over medium heat, stirring, for 2-3 minutes until slightly thickened. Add more water if sauce is too thick.
Serve: Remove skewers from grill and serve immediately. Drizzle warm peanut satay sauce over skewers. Garnish with chopped peanuts, cilantro, or green onions if desired.