In a bowl, combine the coconut milk, curry powder, sugar, and red curry paste. Mix well until smooth, then add the chicken thighs, ensuring they are fully coated. Cover and let marinate for at least 20 minutes.

Soak bamboo skewers in water for at least 2 hours if using. Thread the marinated chicken onto the skewers, packing them snugly.

Heat a non-stick pan over medium-high heat and add a splash of oil. Cook the skewers for about 3 minutes on each side until golden brown and cooked through.

In a saucepan, combine the remaining coconut milk, peanut butter, soy sauce, and cider vinegar. Stir for about 5 minutes until the sauce thickens slightly.

Transfer the cooked skewers to a platter and serve warm with the peanut sauce for dipping. Garnish with cilantro or chopped peanuts.