Makes 1 toastie:
Spread the Dill Mustard Sauce on one side of one of the slices of sourdough. Add 2 slices of Emmental, the salt beef and the sauerkraut. Top with another slice of Emmental and the second slice of sourdough.
Heat a frying pan on a medium-high heat and add the butter until it’s melted and bubbling. Cook the sandwich in the butter for 2-3 minutes until golden brown. Add a little more butter to the pan if needed and cook the sandwich on the other side. Serve with a side of gherkins if desired.