arugula

1 large bunch arugula (about 4 cups) OR 1 large bunch spinach leaves, stems trimmed (about 4 cups) 4 thin slices Prosciutto di Parma (about 2 ounces), cut in 1/2-inch wide strips 1/2 cup shaved or coarsely grated Parmigiano-Reggiano cheese 2 tablespoons toasted pine nuts 1/4 cup prepared...