Put egg in a pot of cold water and boil for about 8 minutes on high heat.

Peel and cut the potatoes into small pieces, put them in a pot, and add water to cover the potatoes. Add 1/2 teaspoon of salt and cook over high heat for about 15 minutes or until softened.

Remove the head and tail of the cucumber and slice it.

Peel and slice shallots.

Put the cucumber slices and shallot slices into the same bowl, add 1 teaspoon of salt to mix well, then marinade until dehydrated.

Peel and chop the carrot.

Boil the potatoes until soft, drain the water, add butter and crushed hard-boiled eggs while they are still hot, and mix well.

Rinse the dehydrated cucumber slices and shallot slices with filtered water or drinking water several times, and squeeze out the excess water before adding it to the mashed potatoes.

Finally, add minced carrot, pepper, and Japanese mayonnaise, mix well and enjoy!