4 plum or roma tomatoes (fresh or canned)
1/2 cup balsamic vinegar
4 tsp dried basil or 1/4 cup fresh basil
2 Tbsp olive oil
1 garlic clove, minced
1/2 teaspoon salt
4 boneless skinless chicken breast halves
Cut tomatoes into quarters and place in a food processor. Add the vinegar, basil, oil, garlic and salt; cover and process until blended.
Pour dressing into a large resealable plastic bag; add chicken. Seal bag and turn to coat; refrigerate for up to 4 hours. (or longer )
Drain and discard marinade. Grill chicken until done, when a meat thermometer reads 170°.