Lay the rouladen out flat on a work surface. Sprinkle with salt and pepper to season.
Drizzle mustard the length of the meat and smear it all over the face of the meat with a knife.
Mix onion and bacon in a small bowl. Sprinkle onion and bacon over the surface of the rouladen leaving about a 1/4 " from the outside edges.
Place a dill pickle spear across the widest end of the rouladen. Starting at the pickle end, roll the meat lengthwise into a roll. Secure with 2 toothpicks.
Repeat with remaining rouladen.
Heat vegetable oil in a large skillet, large enough to eventually hold all 12 rouladen. Brown the rouladen a couple of minutes on each side. You may have to do this in batches. Remove browned rouladen and repeat in batches until they are all browned.
Return all rouladen back to the skillet. Pour enough broth into the skillet to come half way up the rouladen. Add the herbs and spices.
Bring to a simmer, cover and simmer about 90 minutes. Check half way through to see if you need to add more broth to keep the level halfway up the rouladen.
When rouladen is cooked remove the rolls and keep warm. Remove the toothpicks from each rouladen.
Strain and reserve the broth. Discard the solids and return the broth to the skillet. Add water to the cornstarch to dissolve it. Add to the broth and bring to a boil. Stir until it reaches the thickness you want. Depending on how much broth you have you may have to add another Tbsp of cornstarch dissolved in water to get a nicy gravy consistency.
Serve on a platter with gravy on the side.