Chop the onion and tomato into small cubes.boil the Vienna's for 5 mins,and slice the buns until 3/4 way through.set up the Vienna in the bun,top up the onion and tomato,put the mustard sauce.it is ready.

Garnish with tomato sauce or mayonnaise sauce as per preference.*important tip*when placing the Vienna on the bun,put a tbsp of the water it was boiled in onto the sliced part of bun,this makes the buns soft*