Preheat the oven to 200°C.
Pat the fillet dry with kitchen towel. In a small bowl combine the beef rub, mustard and olive oil to form a paste. Rub the paste on the fillet and sear in a hot pan until browned on all sides. Place on a baking dish and into the hot oven for 15 minutes. This will ensure the fillet is nicely browned but still rare inside. Cover loosely with foil to rest for at least 10 minutes before slicing and serving with rustic chips and bearnaise sauce.
To make the bearnaise sauce, clarify the butter by melting in a saucepan and skimming off the foam as the butter reaches a simmer. In a separate saucepan, combine the chopped shallot, vinegar, lemon juice, peppercorns and thyme. Bring to the boil and allow the liquid to reduce to a third of its original volume. Strain the vinegar into a heatproof bowl and discard the flavourings. Place the bowl over a pot of simmering water, taking care that the water does not touch the bottom of the bowl. Add the egg yolks one at a time and whisk over a gentle heat until the mixture is thick and creamy. Take the bowl off the heat, and slowly whisk in the warm clarified butter, adding a splash of water if the sauce gets too thick.
Season with salt and serve immediately.
Serves: 8
Wine suggestions
Most people would pair a Cabernet or Bordeuxstyle blend with this. Boring! Go for something more interesting. Live a little. Try some Cabernet Franc with your steak. It has good weight but the tannins are usually softer. Meaning it holds up to the rich food but goes down more easily. Eikendal and Warwick make delicious ones, but the Raats Family Cabernet Franc is king.