* Sandwich or roll steaks should weigh about 6 oz each. ** Pickles, Salt Pork or Bacon should be cut into long thin strips. ~- Lay steaks on a flat surface. Spread each with mustard; sprinkle with salt and pepper. Divide pickles, salt pork (or bacon), and onion among the steaks equally. Roll up steaks jelly-roll fashion; secure with beef roll clamps, toothpicks, or thread. Heat oil in a heavy saucepan, add the steak roll, and brown well on all sides, about 15 minutes. Pour in hot beef broth, peppercorns, and bay leaf. Cover and simmer for 1 hour and 20 minutes. Remove beef rolls, discard clamps, and arrange on a preheated platter. Blend cornstarch with a small amount of cold water, stir into gravy and bring to a boil. Boil until gravy is thick and bubbly. Correct seasonings and serve separately.