Grilled Lemon-Parsley Chicken Breasts

1. Whisk 3 tablespoons oil, 1 tablespoon lemon juice, parsley, 1⁄4 teaspoon sugar, mustard, 1⁄4 teaspoon salt, and 1⁄4 teaspoon pepper together in bowl and set aside for serving.
2. Whisk remaining 3 tablespoons oil, remaining 1 tablespoon lemon juice, remaining 1 teaspoon sugar, 1-1⁄2 teaspoons salt, 1⁄2 teaspoon pepper, water, and garlic together in bowl. Place marinade and chicken in 1-gallon zipper-lock bag and toss to coat; press out as much air as possible and seal bag. Refrigerate for at least 30 minutes or up to 1 hour, flipping bag every 15 minutes.
   3A. FOR A CHARCOAL GRILL: Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, pour evenly over half of grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.
   3B. FOR A GAS GRILL: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Leave primary burner on high and turn off other burner(s).
3. Clean and oil cooking grate. Remove chicken from bag, allowing excess marinade to drip off. Place chicken on cooler side of grill, smooth side down, with thicker sides facing coals and flames. Cover and cook until bottom of chicken just begins to develop light grill marks and is no longer translucent, 6 to 9 minutes.
4. Flip chicken and rotate so that thinner sides face coals and flames. Cover and continue to cook until chicken is opaque and firm to touch and registers 140 degrees, 6 to 9 minutes longer.
5. Move chicken to hot side of grill and cook until dark grill marks appear on both sides and chicken registers 160 degrees, 2 to 6 minutes longer.
6. Transfer chicken to carving board, tent loosely with aluminum foil, and let rest for 5 to 10 minutes. Slice each breast on bias into 1⁄4-inch-thick slices and transfer to individual plates. Drizzle with reserved sauce and serve.

GRILLED CHIPOTLE-LIME CHICKEN BREASTS
Substitute lime juice for lemon juice and use an extra teaspoon juice in reserved sauce. Substitute minced canned chipotle chile in adobo sauce for mustard and cilantro for parsley.

GRILLED ORANGE-TARRAGON CHICKEN BREASTS
Substitute orange juice for lemon juice and tarragon for parsley. Add 1⁄4 teaspoon grated orange zest to reserved sauce.