This casserole is a saute rather than a braise, and using eye fillet makes this a quick dish to cook as the tenderness of the cut reduces cooking time.
800g eye fillet
1 onion, thinly sliced
1 1/2 tbsp paprika (use a combination of hot and sweet)
300g button mushrooms (halved or quartered if necessary)
3 tbsp olive oil
300ml sour cream (light if preferred)
salt and pepper
juice of half a lemon
fresh parsley, chopped
Slice beef into 1cm strips.
Place a deep, heavy dish on a medium heat, melt butter and fry onion until soft. Add paprika and cook for a couple of minutes, being careful not to let the onion brown.
Add mushrooms and cook for a further 3-5 minutes, remove contents and set aside. If pan is dry, add a dash of cognac or stock to finish and deglaze.
Season beef with salt and pepper, return pan to heat, add half the olive oil and cook beef in two or three batches - you want to seal and caramelise the meat, not stew it.
Remove beef and set aside.
Return mushroom and onion mix to pan, pour in cream, bring to the boil and simmer for a minute until it starts to reduce. Return steak to pan with lemon juice and some parsley.
Serve with tagliatelle.