1/4 cup Dijon mustard
2 tbsp fresh leon juice
1 1/2 tsp Worcestershire sauce
1/2 tsp dried tarragon
1/4 tsp freshly ground black pepper
4 halves chicken breast, boneless, skinless
Combine the first five ingredients, mixing well, spread on both sides of chicken. Place chicken on a plate. Marinate at room temperature for 15 minutes or for seven hours in the refrigerator. Grill, uncovered, over medium coals, turning once, for 10 to15 minutes or until juices run clear.