Method:
Heat a frying pan until hot, then add half the butter. When foaming, add the onion and fry for 2-3 minutes, or until just softened. Add the mushrooms and cook for 1-2 minutes. Add the tomato puree, mustard and paprika and cook for a further minute. Add the beef stock and bring to the boil, then reduce the heat and simmer for 3-4 minutes. Season the beef with salt and freshly ground black pepper. Heat a separate frying pan and add the remaining butter. When foaming, add the beef and fry for 2-3 minutes on both sides, until browned all over. Add the brandy and carefully allow to flambé in the pan. (CAUTION: make sure there are no flammable materials above the pan when flaming.) Add the soured cream to the onion and mushroom mixture and mix well. When the flames have subsided, add the beef to the soured cream and mushroom mixture and cook for one minute. Season, to taste, with salt and freshly ground black pepper and add the parsley.
Note: Serve on a bed of fluffy rice
Source: bigoven.com