Wash the potatoes thoroughly and peel them.
Cut the potatoes into appropriate sizes.
Put the potatoes in a pot and boil them.
Mash the boiled potatoes.
Finely chop the onion and cucumber.
Peel the boiled eggs.
Add the onion, cucumber, and eggs to the mashed potatoes.
Season and mix with mayonnaise, salt, and pepper.
Serve in a bowl to finish.