Mix ingredients into a smooth dough, cover and place in the refrigerator for at least 1 hour.
Mix large potato, browned hamburger, and drained sauerkraut together.
Mix boiled potato, sauteed onion, and grated cheddar cheese together.
Combine dry curd cottage cheese, egg yolk, salt, and pepper together.
While dough is chilling, make the fillings.
Roll out the dough thin into a large rectangle.
Place balls of filling along one end of the dough, then fold over and cut out Wareneki.
Boil the Wareneki in water with butter for 5 minutes if fresh, or 10 minutes if frozen.
Melt butter in a saucepan, stir in sour cream, bring to a boil, then simmer for 5 minutes.
Serve the Wareneki with sour cream, heated whipping cream, sauteed onions, fried crumbled bacon, farmer sausage or fried ham slices, and sauteed red cabbage.
