In a blender or food processor, combine the nuts, 2 tablespoons cilantro, oil, garlic, soy sauce, sugar, lime juice, jalapeno, and 2 tablespoons water.
Blend until smooth, scraping down the sides as necessary.
Taste and season with salt and pepper, if desired.
Season the chicken all over with salt and pepper.
Smear on enough cashew mixture to coat the pieces thoroughly, but don't make it too thick or the sauce will fall off into your grill (set aside any remaining mixture).
Let marinate at room temperature while you heat the grill or broiler.
Or refrigerate for up to 12 hours before cooking.
Preheat the broiler or grill.
Grill or boil the chicken, turning frequently, until it is crisp and golden on the outside and done on the inside, 20-30 minutes.
Sprinkle the chicken with the remaining 4 tablespoons cilantro and serve lime wedges and the remaining cashew mixture.