Cut the cucumber into thin slices with a kitchen slicer and drain in a kitchen sieve. Add a teaspoon of salt and stir several times with a tablespoon while pressing down a little so that the water is squeezed out. Cut the spring onion into rolls and the onion into small cubes and add.
Mix the ingredients for the dressing in a bowl. Fold in the cucumber slices and sheep cheese.
Let it steep in the refrigerator for 20-30 minutes, then serve.