How to Make It
In a medium bowl, stir the brown sugar with the mustard, coriander and jalapeño and season with salt and pepper. Scrape the mixture into a large resealable plastic bag. Add the chicken drumsticks and turn to coat. Seal the bag, pressing out the air; refrigerate the chicken overnight.
Light a grill and oil the grate. Remove the chicken from the marinade and season with salt and pepper. Grill the chicken over moderately high heat, turning occasionally, until browned all over, 10 to 12 minutes. Transfer the chicken to a plate.
Wrap the soaked wood chips in a double layer of foil and poke holes in the top of the packet. Remove the grill grate. Turn the heat off on half of the grill or rake the coals to one side. Set the wood chip packet directly on the coals or flames and replace the grill grate. When the chips are smoking, return the chicken to the grill over indirect heat. Cover the grill and smoke the chicken until an instant-read thermometer inserted in the thickest part of the drumsticks registers 165°, about 30 minutes. Transfer the chicken to a platter and serve.
The grilled, smoked chicken can be refrigerated overnight.