Whisk together chives, thyme, pesto, mustard, lemon juice, oil, and lemon rind.
Lay chicken in a shallow dish and spoon 1/2 cup mixture overtop both sides of chicken. Wrap with plastic wrap and chill 1 to 4 hours.
Arrange chicken on a cooking spray coated grill rack. Grill 10 minutes or until chicken is fully cook, flipping a few times; brush the rest of the mixture over chicken frequently while grilling. Top with sage sprigs before serving.