Transfer to a rack in a roasting tin, uncovered and place in the oven, cook for 15 - 18 minutes for Rare, 20 - 25 minutes for Medium.

Take the fillet out the oven and rest on a rack, covered with foil in a warm place for 10 minutes.
Remove to a carving board and carve into slices.

Serve with: potato and celeriac rosti, and a wild mushroom medley.