Beef and mushroom goulash

1) Peel onions and chop finely and leave to stand for 10 minutes
2) Chop the garlic finely and leave to stand for 10 minutes
3) Cut the meat in 2.5 cm chunks.
4) Cut the mushrooms into quarters.
5) Put the butter and oil into a frying pan. Add the onion and garlic and cook, covered, over a low heat until transparent. Turn constantly to ensure they cook evenly but don't brown. Remove from the pan.
6) Increase heat, add the meat and brown. Don't overcrowd the bottom of the pan, you may need to brown in batches.
7) Add onions and garlic back to the pan, sprinkle with the flour and stir. When flour begins to colour, pour in stock and add the mushrooms, paprika, caraway seeds, wine vinegar, salt and pepper.
8) Stir well, cover and simmer for 1½ hours over a moderate heat until meat is tender.