Take the ends off the cucumber, and slice diagonally.
Put the cucumber and salt in a plastic bag, and massage over the bag.
When the cucumber slices have wilted, add the mustard and sugar and massage over the bag again. Serve.
Story Behind this Recipe
Japanese-style mustard pickles are delicious, so I thought another more "Western" version using mustard should be great too.
By slicing the cucumber diagonally, it will wilt faster. By using a plastic bag, you'll be able to prevent your hands from getting dirty. I added a little sugar for sweetness. Serve these just like you would any other kind of pickle.