Yeast-free potato doughnuts

Potatoes are cooked in the skin, peeled and passed through a meat grinder. 1 glass of water is poured into the pan, fat and salt are put, put on fire. When the water boils, all the flour is poured in at once, thoroughly stirred over the fire for several minutes, after which it is left to cool. Mashed potatoes and egg are added. It is stirred until a homogeneous mixture is obtained. One spoon of this mixture is taken, doughnuts are fried in a saucepan with a lot of warmed vegetable oil, browned on both sides. Served at the table warm, sprinkled with vanilla sugar.