Preheat the oven to 375 degrees F. Preheat the grill. Place the walnuts on a baking sheet and cook for 5 to 6 minutes, or until golden, be careful not to burn the nuts. Remove from the pan and place in a mixing bowl. Toss the walnuts with the vinegar. Season with salt and pepper. Set aside and cool. Cut the radicchio into fourths. Season with olive oil, salt and pepper. Grill for 2 minutes on each side. Remove and cool. With a sharp knife, julienne the lettuce. Whisk the walnut oil into the walnut mixture. Season the dressing to taste with the honey. In a mixing bowl, combine the arugula, radicchio and endive together. Season with salt and pepper. Toss the lettuces with the dressing. Mound the greens in the center of each plate. Crumble the cheese over the salad and garnish with fresh cracked pepper. Serve immediately.