How to Make It
In a large bowl, combine the sherry, soy sauce and sugar. Add the chicken pieces and marinate at least 1 hour and up to 8 hours.
Light a grill or preheat a grill pan. Grill the chicken over moderately high heat, turning occasionally, until the chicken is lightly charred and cooked through, about 20 to 25 minutes. Transfer the chicken to a work surface and let rest for 5 minutes.
Meanwhile, in a small saucepan, bring the sherry–soy sauce marinade to a boil. Cook for 1 minute. Serve the chicken garnished with the cilantro and with the sauce on the side.