Balsamic and mustard marinade brings a balance of sweet, savory, and tart to the smoky grilled chicken. Make extra for dipping or for tossing with veggies.
Whisk together the vinegar, mustards, garlic, brown sugar, lemon juice, paprika, onion powder, salt, and pepper.
Pour the marinade over the chicken and refrigerate for 1 hour. Can rest for 8 hours if preparing ahead of time.
Heat grill to medium-high then add chicken. Cover and cook 20 to 30 minutes, or until chicken is done. While it's cooking, turn and baste it as needed.