Cut bread in half lengthwise; carefully hollow out top and bottom, leaving ½ inch shells (discard removed bread or save for other use). Spread 3 tablespoons of butter and all of the mayonnaise inside bread shells. Line bottom bread shell with ham, turkey, and bacon. Top with tomato, onion and honey mustard.
In a skillet, melt remaining butter; add eggs. Cook over medium heat, stirring occasionally until eggs are almost set. Spoon into bottom bread shell; top with cheeses. Cover with bread top. Wrap in greased foil. Bake at 375ºF for 15 - 20 minutes or until heated through. Cut into serving size pieces.