1. Peel, chop and boil potatoes, drain and mash.
2. Chop onion finely, press garlic and chop up walnuts, add all to the mashed potatoes. Add salt and pepper and mix well.
3. Thinly slice the cucumber from tip to bottom. Spoon out a lump of mixture and roll it in the cucumber.
4. Place the grated radish on top of the rolled cucumber, enjoy!