How to Make It
In a large mixing bowl, combine the mustard, syrup, salt, pepper and chile powder. Add the chicken thighs and toss until well-coated, then set aside.
Set up grill for indirect grilling. On a gas grill, turn all burners on high heat for 10 minutes, then turn off the burners on one side of the grill. On a charcoal grill, bank the hot coals on one side of the grill.
Place the chicken on the cool side of the grill and cook until a quick-read thermometer registers 165° near the bone, about 35 minutes. Rotate the chicken halfway through so that all the pieces have equal time near the hot side of the grill to encourage even cooking. Alternatively, roast in a 400° oven for 40 minutes.