Slit the top of the fillet about halfway through.
Very finely chop anchovies, garlic and parsley and season with pepper.
Squash the mixture into the fillet nd tie with string.
Rub fillet with olive oil and season with pepper.
Lightly oil a pan and heat until smoking hot.
Sear meat to brown on both sides - about 90 seconds each side.
Place on a baking tray and roast in a preheated 200 °C oven for eight to 10 minutes.
Remove from oven, cover with foil and allow to rest for at least 10 minutes before carving.
To tie with string
Tie a small knot at one end of the meat and leave about 120 centimetres hanging loose.
Stretch about two centimetres of string along the side of the meat and hold it down with your finger.
Lift the meat and swing the loose end underneath the fillet, keeping the two-centimetre piece stretched with your finger.
Loop the loose piece that went underneath the meat into the piece that you are holding with your finger.