Preheat oven to 350 degrees. Line a baking sheet with foil and set aside.
To make bread crumbs: break up bread and add to a blender or food processor. Process for a few seconds, until the bread turns into crumbs.
In a large bowl, add ground beef. To the beef, add bread crumbs, onions, egg, 1 tablespoon each, ketchup, mustard, relish and Worcestershire. Mix in a little pepper and seasoning salt, if desired. Using your hands, mix together all the ingredients, until well combined.
Place meat mixture on baking sheet and free form a loaf by hand. It should be about 12 x 3 inches. Bake for 40 minutes.
In the meantime, In a small bowl, mix together toppings; ketchup and mustard. Remove meatloaf from oven once baked for 40 minutes. Spread the ketchup and mustard mixture all over top of meatloaf. Top evenly with shredded cheese. Place back in oven and bake about 5 minutes more, until cheese melts.
Remove from oven and let rest for at least 10 minutes, before slicing.