Hannah's Barbecued Chicken

6 SERVINGS

1 cup light brown sugar
1/2 cup cider vinegar
1/4 cup olive oil
1/4 cup fresh lemon juice
6 garlic cloves, smashed
3 tablespoons grainy mustard 
2 tablespoons fresh lime juice
2 teaspoons Worcestershire sauce 
1/2 teaspoon finely grated lime zest 
12 skinless boneless chicken breast halves (about 6 ounces each), lightly pounded
Salt and freshly ground pepper

1. In a blender, combine the brown sugar, vinegar, olive oil, lemon juice, garlic, mustard, lime juice, Worcestershire sauce and lime zest. Blend until smooth. Arrange the chicken breasts in a large nonreactive dish and pour the marinade on top. Let stand at room temperature for up to 1 hour, turning occasionally. 

2. Light a grill or heat a grill pan. Remove the chicken from the marinade. Season the chicken with salt and pepper and grill until browned and cooked through, about 3 minutes per side. Serve hot or at room temperature.