In a large bowl, combine the chicken cubes, kecap manis, lime juice, garlic, shallots, turmeric, coriander, cumin, salt, and black pepper. Toss to coat the chicken evenly. Cover and refrigerate for 30 minutes to 4 hours, allowing the flavors to marinate.
While the chicken is marinating, prepare the peanut sauce. In a small saucepan, whisk together the coconut milk, peanut butter, kecap manis, lime juice, chili peppers (or crushed red pepper flakes), garlic, and ginger. Bring the mixture to a simmer over medium heat, stirring frequently, until the sauce is smooth and creamy, about 5 minutes. Reduce the heat to low and keep the sauce warm until ready to serve.
Preheat your grill or barbecue to medium-high heat.
Thread the marinated chicken cubes onto skewers, leaving a small gap between each piece to ensure even cooking.
Grill or barbecue the satay skewers for 2-3 minutes per side, or until the chicken is cooked through and slightly charred. Baste the chicken with any remaining marinade during the cooking process.
Serve the grilled satay chicken skewers warm, accompanied by the peanut sauce, steamed rice, cucumber slices, red onion, and fresh cilantro or mint leaves.