Shaved Kohlrabi with Apple and Hazelnuts

Name: Shaved Kohlrabi with Apple and Hazelnuts
Ingredients: ½ cup blanched hazelnuts; 2 medium kohlrabi (about 2 lb. total), peeled, thinly sliced on a mandoline; 1 tart apple (such as Pink Lady or Crispin), peeled, cored, thinly sliced on a mandoline; ½ teaspoon finely grated lemon zest; 1 tablespoon fresh lemon juice; 1 tablespoon white wine vinegar or white balsamic vinegar; Kosher salt; ½ cup torn fresh mint leaves, plus more for serving; 1 tablespoon extra-virgin olive oil; 2 oz. Pecorino di Fossa or Parmesan, shaved (about ¼ cup)