YIELD: Serves 4
1 Tbsp. canola oil
1/2 tsp. salt plus 1/8 teaspoon, divided
1/2 tsp. ground pepper
2 bone-in, skinless chicken breasts, cut in half crosswise
1 cup blueberries, fresh or frozen (thawed), coarsely chopped if large
1/2 serrano or jalapeño pepper, or to taste, finely chopped
2 Tbsp. finely chopped shallot
1 Tbsp. chopped fresh cilantro
Zest lime (reserve the fruit). Combine the zest, oil, 1/4 teaspoon salt and pepper in a small bowl. Place chicken in a shallow dish meat-side up and spoon the mixture on top. Cover and refrigerate for at least 2 hours and up to 8 hours (see Tips, below).
Preheat grill to medium.
Oil the grill rack (see Tips, below). Grill the chicken until an instant-read thermometer inserted in the thickest part without touching bone registers 165°F, 8–12 minutes per side. Transfer to a serving plate; let rest for 5 minutes.
Meanwhile, slice ends off the reserved lime. With a sharp knife, remove the white pith and discard. Cut the segments from their surrounding membranes and coarsely chop. Combine in a small mixing bowl with blueberries, chile, shallot, cilantro and the remaining 1/8 teaspoon salt, stirring gently. Serve with the chicken.
Make Ahead Tip: Marinate chicken for up to 8 hours.
Oiling a grill rack before you grill helps prevent foods from sticking. Once the grill is heated, oil a folded paper towel, hold it with tongs and rub it over the rack. Do not use cooking spray on a hot grill.