Dressing: combine olive oil, balsamic vinegar and salt. Mix well. Set aside.
In a large skillet, cook pancetta until crisp. Put on paper towel to drain. In the same skillet and in the drippings from the pancetta, add pear slices and cook 5-7 minutes or until lightly browned and tender, stirring occasionally. Keep warm.
In a large bowl, combine arugula, onion slices and dressing. Gently toss to coat.
Divide the arugula mixture among six plates. Arrange pear slices on top. Sprinkle with pancetta, pine nuts and gorgonzola cheese. If desired, sprinkle with freshly ground black pepper.