Cut the crusts from the bread and using a rolling pin, roll to make the bread a little pliable.
Spread thinly with the mustard making sure it reaches the edges evenly, then drizzle over a little curry ketchup, if used.
Place a Frankfurter at the top end and tuck in a couple or more the gherkin slices.
Roll up quite firmly, place joint side down on a baking tray and secure with a wooden toothpick.
Brush the top and sides with the melted butter.
Bake for 12-15 minutes until golden brown and crisp. Remove and cool until warm.
Take out the sticks before serving.
Note: Burkhardt, Zeisner, Hela are some of the brands that make curry ketchup. Check out your local gourmet stores, look in the european isles of the local supermarkets, order offline, or make your own. Combine small amounts of ketchup and curry until you reach your desired taste.