Start by peeling and washing your potatoes, then place them in a pot of water to boil on high heat with 1 teaspoon salt. Once they become soft enough to mash with a fork, mash all of them. This can take around 15-20 minutes depending on the heat of your stove
Boil your eggs until they are hard boiled. Once they are hard boiled, separate and reserve 1 whole egg yolk. Mash or grate the single egg yolk and set aside to use for garnish later. Cube the remaining egg whites and egg yolk and set a side. *If you don’t really care for the garnish you can just dice the eggs without separating 1 yolk.
Wash and cut your cucumbers in half along the long side, then slice them about as thin as a coin (This should produce half moon shaped cucumbers). Sprinkle ¼ teaspoon of salt on the sliced cucumbers, then mix them thoroughly to ensure that they all have some salt. Let them sit for about 5-10 minutes so the excess water releases. After rinse them in cold water and squeeze any excess water out. Set them aside for later.
Peel, wash, and dice your apple into 1 cm cubes. Then set aside.
Once you have completed all of the previous steps, in a large bowl combine the mashed potatoes, and cucumber. Mix until they are well combined.
Add in the mayo, 1 teaspoon salt, sugar, and black pepper. Stir until well combined.
Add in the diced egg whites and egg yolk, then gently mix to incorporate.*If you reserved and egg yolk and mashed/grated it, do not add that in at the step.
Taste and adjust salt/sugar if needed. If everything is all set, you can serve as is or chill and serve when needed! It can be store in an airtight container in the fridge for about 3 days.