Mustard goes with almost anything. In this case the spicy Dijon mustard is incorporated into a marinade along with brown sugar to add a subtle sweetness.
3 tablespoons Dijon mustard
1 tablespoon brown sugar
1/2 teaspoon salt
1/4 teaspoon black pepper
1 large, boneless, skinless half chicken breast
Combine the first 4 ingredients (mustard through pepper) in a small bowl and thoroughly mix. Place the chicken between two pieces of plastic wrap and pound to a uniform thickness of approximately 1/2 inch thick. Brush the mustard mixture on all sides of the chicken, place it on a plate and cover with plastic wrap. Marinate refrigerated for 1 to 3 hours.
Prepare the grill for hot direct cooking. Place the chicken directly over the fire for 5 minutes per side, then turn and cook for an additional 2 minutes on the first side.