In a small bowl, combine the first five ingredients; set aside. Make 11 slices in the bread, not cutting all the way though bottom crust. Place loaf on a piece of foil large enough to wrap it completely. Gently separate every other slice and spread 1 tablespoon mayonnaise mixture on cut surfaces. Insert cheese, tomato, salami, onion and pepperoni between every other slice. Wrap the foil tightly around loaf; place on a baking sheet. Bake at 350° for 25 minutes. To serve, cut bread between unstuffed slices; serve warm.
Editor's Note: This loaf can be made ahead and refrigerated before baking.
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