Peel, wash and slice potatoes, grate onions.
Saute onions in vegetable oil over medium heat for 2-3 minutes. Be careful not to burn them.
Take off the heat, add paprika and ground bay leaves, stir. Add potatoes and stir again. Cook without adding water for 1-2 minutes, stirring frequently.
Add 2 cups (480 ml) of water (won't cover the potatoes completely), whole bay leaves, tomato purée and green peppers. Cook covered over low heat for 15 minutes, until potatoes become tender.
In a bowl mix sour cream and flour. Add 4-5 tbsp of the potato liquids and mix to distribute heat.
Pour sour cream mixture over the dish and mix smoothly not to break the potatoes too much. Let it come to a boil and cook for 2-3 minutes over low heat to cook the flour.