Wash the potatoes and cucumber. Place the potatoes in a saucepan and cover with cold water. Add a pinch of coarse salt and cook for 20 minutes over a medium heat.
Meanwhile, cut the unpeeled cucumber into small rods.
When the potatoes are cooked, remove them from the pan using a slotted spoon and cut them in half once they have cooled.
Spread the potatoes with tarama, cover with small cucumber rods and drizzle with lemon zeste and serve!