Place the chicken breasts in a large ziplock bag. Add 2 tablespoons balsamic vinegar, 2 tablespoons olive oil, salt and pepper. Seal and toss the chicken in the marinade to coat. Set aside.
Preheat the grill to medium-high. Clean the grates and lightly oil to prevent sticking.
In a medium mixing bowl, whisk together 2 tablespoons balsamic vinegar, ¼ cup olive oil, honey, ½ teaspoon salt and 1 teaspoon fresh ground black pepper. Add the sliced nectarines and onion. Toss to combine and set aside while grilling the chicken.
Grill the chicken until done through - about 5 minutes on each side. Serve topped with the nectarine and onion relish and fresh chopped basil or small basil leaves. You can always add a little more fresh ground black pepper on top. Enjoy!
Notes
Inspired by a recipe in Country Living Magazine
Nutrition information is calculated using an ingredient database and should be considered an estimate. When multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.