Alfred Portale serves this salad at his Gotham Bar & Grill restaurant in New York City. You can substitute two Granny Smith apples for the pears for a more tart salad.
Preheat the oven to 350 degrees. Place walnuts on a baking sheet. Toast, stirring occasionally, until crisp and fragrant, 10 to 12 minutes. Transfer walnuts to a bowl, and let cool.
Coarsely chop the walnuts. In a large bowl, combine the endive, radicchio, watercress, and parsley. Drizzle with the vinaigrette, lightly coating all ingredients. Add the cheese, toasted walnuts, and pear slices. Season with salt and pepper. Toss well, and serve immediately.