Whisk together all ingredients in a large non-reactive bowl. Prick turkey breast with a fork and add to the marinade, turn to coat completely. Refrigerate covered, for at least 4 hours. Preheat grill and grill the breast for 1 to 1 1/2 hours until golden brown and cooked through.
Succotash Salsa: Mix all ingredients together in a medium bowl and season with salt and pepper to taste. Let sit 30 minutes. Serve at room temperature.