- Season the meat with salt, pepper and Worcestershire sauce.
- Put a large heavy-bottomed saucepan over a high heat.
- Add 3 tbsp olive oil and when hot, add half the beef.
- Stir-fry briskly until lightly browned.
- Set aside in a bowl, add 2 tbsp more oil to the pan and repeat the process with the remaining meat.
- Remove the second batch of seared meat and its juices, reduce the heat and melt the butter in the saucepan.
- Add the onions, the garlic and gently fry until very soft.
- Add the mushrooms to the stir fry and cook until tender.
- Add the meat with any juices and pour over the cognac or red wine.
- Immediately set alight and shake the pan until the alcohol has burnt itself out.
- Stir in the sour cream or yogurt.
- As soon as it is hot, mix in the lemon juice, season to taste and sprinkle with a little paprika and nutmeg.
- Serve immediately with steamed or boiled white rice.