To prepare the chicken, in a large bowl, combine the ginger, garlic, sugar, oil, turmeric, cumin, 1½ teaspoons salt and ½ cup water. Stir until the sugar dissolves, then stir in the chicken. Cover and refrigerate for 2 to 3 hours.

To make the sauce, in a medium bowl, whisk the boiling water and peanut butter until smooth. Whisk in the soy sauce, vinegar and sugar, then set aside. In a small skillet over medium, heat the oil, ginger and garlic. Cook, stirring constantly, until fragrant, about 1 minute. Stir in the chili-garlic sauce and turmeric, then cook until fragrant, about 30 seconds. Whisk the garlic mixture into the soy mixture. Reserve ¼ cup for basting the chicken. Cover and refrigerate the remaining sauce for serving.

About 30 minutes before skewering and cooking the chicken, remove the sauce from the refrigerator. Stir in the chopped peanuts. Heat the broiler with a rack about 4 inches from the element. Line a rimmed baking sheet with foil and spread 1 cup salt in an even layer over it. Set a wire rack in the baking sheet over the salt and mist with cooking spray.

Drain the chicken in a colander. Thread 2 or 3 pieces of chicken onto each of eight 8-inch metal skewers, evenly dividing the meat and pushing the pieces together, but not tightly packing them. Evenly space the skewers on the wire rack.

Broil the chicken until beginning to brown, 5 to 7 minutes. Flip the skewers and continue to broil until the second sides begin to brown, another 4 to 6 minutes. Remove from the oven and brush each skewer with 1 to 2 tablespoons of the reserved sauce. Continue to broil until well-charred, 2 to 4 minutes. Remove from the oven once again, flip the skewers and brush with another 1 to 2 tablespoons of the reserved sauce. Continue to broil until the second sides begin to char and the chicken is cooked through, another 2 to 4 minutes. Serve with the dipping sauce.