Mix the spices together in a bowl. Salt and pepper the pork shoulder, then sprinkle with the spices. Place it in the bag with the Worcestershire sauce and the liquid smoke. Seal the bag, place it in the water bath, and cook for 18 to 24 hours, until tenderized.
Whisk together all the ingredients in a bowl.
Take the sous vide bag out of the water and remove the cooked pork. Dry it off thoroughly, using paper towels or a clean dish cloth. Lightly salt the pork shoulder, then quickly sear it for 1 to 2 minutes per side, just until browned. Remove it from the heat and shred.
Serve on rolls with pickles and cabbage, with a spoonful of the mustard-vinegar sauce on top.