To toast the hazelnuts
Preheat the oven to 350 degrees.
Place the hazelnuts on a baking pan. Roast for 8 minutes or until lightly toasted and fragrant. Remove from the oven, let cool slightly then coarsely chop in either a food processor or place in a plastic bag and crush with a rolling pin. (note: If the hazelnuts have skins, they will blister off during the baking process. Place the warm nuts in a kitchen towel and “rub” them until the skins come off).
To prepare the vinaigrette
Place the balsamic vinegar in a small bowl. Add the honey, salt and pepper. Slowly whisk in the olive oil until you have vinaigrette with a nice consistency. Taste the vinaigrette. If too tart add a little more olive oil. If not tart enough, add a little more balsamic vinegar.
To prepare the pears
Wash the pears and dry off. Using a thin-bladed knife or Japanese-style mandoline, slice the pear halves into 1/8 inch thick pieces. Do one side of the pear, then the other, avoiding the seeds in the middle. Fan pear slices around 6 salad plates. If making ahead, the pears can be placed in cold water with 2 teaspoons of lemon juice. Make sure the pears are immersed in the water.
In a small bowl, toss the greens with enough vinaigrette to just coat. Arrange a bouquet of greens in the middle of each plate so that the pears are still exposed
Using a vegetable peeler, finish each plate with curls of Parmesan cheese. Drizzle with a bit more vinaigrette if desired and sprinkle with some of the toasted hazelnuts.