Peel and slice the onions and garlic. Remove the stalk from the chestnut mushrooms and thinly slice.
Cut the beef into strips and pan fry in a very hot pan with the sunflower oil for 30 seconds. Remove from the pan and drain in a colander.
Return the pan to the heat and add the butter, onions, paprika and garlic. Cook over a medium heat until the onions start to soften, then add the mushrooms and tomato puree cook for a further 2 minutes or until the mushrooms are soft. Deglaze the pan with the brandy and vodka, remove from the heat and add the the soured cream, mustard and sealed beef. Check the seasoning.
Was the rice under cold water until clear. Bring to the boil in the water with a pinch of salt, then reduce the heat to a simmer, cover with a lid and cook for 8-10 minutes or until all of the water is absorbed.
Spoon the rice onto one side of the plate and the stroganoff on the other side.
«If you cannot find soured cream, use double cream and reducing it by half to thicken it slightly.»