The main mistake when cooking potatoes is named

Before cooking potatoes, they should not be dipped in cold water, as the vegetable can lose most of its nutritional value.

This is reported by kuchnia.wp.pl. It is noted that cooking potatoes is not such a simple action. According to the author of the material, a much more appropriate way would be to put raw potatoes in boiling water and add salt only when the potatoes soften.

Thoroughly washed or peeled young potatoes are cooked for 15-20 minutes over medium heat. It is recommended to boil old potatoes in their skins, as all the most valuable things are under the skin. Later, when peeling, the skin should be cut off as thinly as possible. Potatoes that will be mashed should be cut into small pieces before cooking. This will reduce the time of heat treatment.

You can make potatoes even tastier by adding milk (in the proportion of 250 milliliters per liter), butter, and onions to the water during cooking.