Method

Heat half the vegetable oil in a frying pan until hot.

Add the beef fillet and fry until browned on all sides - this should take no more than 2 minutes in total

Remove the beef from the pan and set aside to cool. Wipe out the pan to use later.

The beef can be held in the fridge at this point.

Heat the oven to 60C

Wrap the cooled beef fillet in cling film and place onto an oven tray. Place in the low oven for 30 mins.

(NB check the clingfilm will be suitable for the oven)

After 30 mins remove the meat from the oven.

Remove the cling film.

Heat the frying pan with the butter and remaining oil until hot.

Slice the beef fillet into 4 large slices, season with salt and black pepper.

Place in the hot pan and fry quickly, 30 seconds on each side.

There is no need to rest the meat.

Serve with your favourite sauces and potatoes.

To achieve the really rare look, leave the beef fillet whole when finally fried, this will keep the meat from browning up. then slice and serve.