1/2 cup maple syrup
3 tablespoons cider or red wine vinegar
2 tablespoons Dijon mustard
1 tablespoon vegetable oil
2 garlic cloves, minced
3/4 teaspoon pepper
6 (4 ounce) boneless skinless chicken breast halves
In a bowl, combine the first six ingredients; mix well. Reserve 1/4 cup for basting; cover and refrigerate. Pour remaining marinade into a large resealable plastic bag or shallow glass container; add chicken and turn to coat. Seal or cover; refrigerate for 4-8 hours, turning occasionally. Drain and discard marinade. Grill, uncovered, over medium heat for 3 minutes on each side. Grill 6-8 minutes longer or until juices run clear, basting with the reserved marinade and turning occasionally.