Preheat oven to 350°. Cut top half off loaf of bread. Carefully hollow out both halves of loaf, leaving a 1/2-in. shell (discard removed bread or save for another use). , Combine remaining ingredients. Spoon into bottom half of bread, mounding as necessary; replace top. Wrap in foil. Bake until cheese is melted, about 25 minutes. Slice and serve warm.