Adapted from Nami Nami

In a hot pan add the butter and wait until it melts before you add the onions. Fry the onions on medium heat with a little salt to draw out the water, just until they become translucent - about 7-8 minutes.
Once the onion has broken down add the meat and allow to fry for 1-2 minutes before breaking up into very small pieces. Cook until there is no more visible pinkness then add the tomato paste and flour.
Cook for 1-2 minutes until all the flour is absorbed and the tomato paste bubbles slightly then add the stock and cook for about 10 minutes until it thickens into a sauce.
Turn the heat off and add a few tablespoons of sour cream and mix thoroughly. Adjust seasoning and serve hot.
4 servings