Ingredients

• 4 (6-ounces) skinless boneless chicken breast halves
• 1/4 cup extra-virgin olive oil
• 1/4 cup chopped dill
• 3 tablespoons finely chopped shallot
• 1 tablespoon grainy mustard
• 1 tablespoon white-wine vinegar
• 1 pintcherry tomatoes, quartered

Instructions

1. Prepare grill for direct-heat cooking over hot charcoal (medium-high heat for gas); see Grilling Procedure .
2. Pound chicken 1/4 inch thick between 2 sheets of plastic wrap with flat side of a meat pounder or with a rolling pin.
3. Whisk together oil, dill, shallot, mustard, and vinegar in a large bowl. Set aside 1/4 cup. Sprinkle chicken evenly with 1 teaspoon salt and 1/2 teaspoon pepper, then add to dill mixture, turning to coat.
4. Toss tomatoes with reserved dill mixture and 1/4 teaspoon each of salt and pepper.
5. Grill chicken, turning once, until just cooked through, 3 to 4 minutes total. Serve topped with relish.