Carefully cut the nectarines in half and remove the stone. In a small bowl, whisk together 1tbsp of balsamic vinegar and 1tbsp of olive oil and dip the nectarines in the mixture and toss them around. Grill them for just a few minutes each side until they are lightly colored.
Meanwhile, add the remaining vinegar and oil to the leftovers from tossing the nectarines and whisk.
Put the arugula in a salad bowl. Thinly slice the fennel and cut larger slices in half or smaller. Add them to the arugula and mix. Drizzle over the balsamic dressing and toss well.
Toast the pine nuts either in a dry skillet/frying pan or under the broiler/grill for a couple minutes until lightly browned. Keep an eye on them as they burn quickly. Add them to the salad.
When cooked, cut the nectaries into slices and add to the salad. Crumble the goats cheese on top and serve.