2Whisk together orange-juice concentrate, chipotle pepper, vinegar, molasses and mustard in a small bowl.
3Lightly oil the grill or broiler rack (see Tip). Season chicken with salt and grill or broil for 2 minutes. Turn, brush with the glaze and cook for 4 minutes, brushing occasionally with glaze. Turn again, brush with the glaze, and cook until the center is no longer pink, 1 to 2 minutes longer.
Note: Chipotle chiles in adobo sauce are smoked jalapeños packed in a flavorful sauce. Look for the small cans with the Mexican foods in large supermarkets. Once opened, they'll keep up to 2 weeks in the refrigerator or 6 months in the freezer.
Tip: To oil a grill rack: Oil a folded paper towel, hold it with tongs and rub it over the rack. (Do not use cooking spray on a hot grill.) When grilling delicate foods like tofu and fish, it is helpful to spray the food with cooking spray.