Lay dinner cuts on a flat surface, and cut in half lengthwise. Spread each with mustard; sprinkle with salt and pepper. Divide pickles, bacon bits, and onion among the dinner cuts equally.
Roll up dinner cuts jelly-roll fashion, secure with beef-roll clamps, toothpicks, or thread.
Heat oil in a heavy saucepan, add the dinner cuts, and brown well on all sides, about 15 minutes.
Pour in hot broth, peppercorns, and bay leaf. Cover and simmer for 1 hour and 20 minutes.
Remove dinner cuts, 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.