Preheat oven to 450 degree f. Cut the bread loaf in half horizontally. Hollow out bread loaf, leaving a 1/2-inch shell. Set bread pieces aside for another use. Place bread halves, hollow sides up, on a baking sheet. Bake in the preheated oven about 5 minutes or until toasted. Set aside to cool.
Spread the inside bottom half of the bread loaf with the pesto. Sprinkle with pine nuts and pepper. Layer turkey, prosciutto, radicchio, greens, cucumber, and onion over nuts. Spread the inside top half of the bread loaf with the mayonnaise. Replace top of bread. Cover and chill for 2 to 8 hours. Slice to serve. Makes 8 servings.