• Pre-heat the oven to 150°C / 300°F (fan-forced).
• Rub the fillet in the olive oil so it is well coated. Then season with the sea salt and pepper.
• Heat a cast iron or oven proof pan over a moderately high heat and sear the beef on all sides so it is dark brown and caramelised on all edges. Use tongs to turn it.
• Then, simply place in the oven to roast (uncovered) for about an hour or until almost cooked to your liking.
• I have a meat thermometer which I think is invaluable for getting this perfect. I cook this to med-rare, then wrap it tightly in foil to rest for about 30 minutes or more. This is really important and makes it super moist.
• To make the tahini sauce, mix all the ingredients together in a serving bowl.

Serve

• When ready to serve, slice the beef and then pour over the pan juices and juices from the foil wrapping.
• Enjoy immediately with the tahini sauce and your favourite sides and salads.
• My family also love this with various mustards.

Store

• In an airtight container in the fridge.
• Left overs are great to make a roast beef sandwich, roll, wrap or salad.