You can't buy this in a store. I tried it once and stopped buying it in the store.

Recipe:
Milk - 300 ml
Salt - 1 tsp
Sugar - 1 tbsp
Egg white - 1 pc.
Yeast - 1 tsp
Flour - 500 gr
Vegetable oil - 2 tbsp
Butter - 150 gr

Filling:
Potatoes - 900 gr
Onion - 2 pcs.
Salt, black pepper to taste
Cheese - 100 gr