Swiss - Orient - Express
put all the ingredients for the brine except for the beef into a saucepan and bring to the boil to simmer for a few minutes, then leave to cool.
place the beef and the cooled liquid into a water-tight container, make sure the beef is fully submerged and leave in the fridge to soak for at least 2 days… up to a week is good.
rinse the beef and soak in clean, cold water for 2 hours, then rinse again. put the beef and chopped vegetables into a pan and fill with water until it covers the beef.
simmer very gently for about 3 hours until the beef is tender, then drain and slice.
slice the bagels into halves. mix the mustard and mayonnaise together and spread on the bagels