1 large head radicchio (3/4 pound), cored and coarsely shredded
5 ounces arugula
1/4 pound Crucolo, Provolone, Taleggio, or Fontina cheese, grated
1/2 cup roughly chopped, lightly toasted hazelnuts
Saba vinegar for drizzling (balsamic vinegar works too)
Heat the broiler to high.
Whisk the red wine vinegar with 1/4 cup olive oil in a large bowl and season generously with salt and pepper. Add the radicchio and arugula and toss to coat them nicely. Taste and adjust the seasoning.
Pile the salad on ovenproof plates or an ovenproof platter and top with the cheese. Broil the salad just until the cheese is melted, about 1 minute. Sprinkle the toasted hazelnuts on top and finish with a drizzle of Saba vinegar. Serve right away.