Remove the steak from the fridge for at least 20 minutes before cooking to bring to room temperature. While it comes to temperature, season the steak well with salt & pepper on both sides. Set on a wire rack over a roasting tray and leave uncovered until you are ready to cook. Preheat the oven to 140˚C. Place the steak in the oven for approx 25-35 minutes for medium rare. If you have a meat thermometer, the temperature should read 55˚C.

While the steak cooks, peel and slice the potatoes into skinny chips.

Place in a large heavy based casserole or dutch oven and pour over the oil until it covers them. Give them a little mix around to make sure the oil has coated each chip. Place over a high heat and bring to a steady boil. Reduce the heat to medium and cook for 15 minutes before gently moving with tongs to loosen any that are stuck to the base of the pot. Continue to cook for a further 5 minutes or so or until they turn golden brown.

Remove the chips with a slotted spoon to a baking sheet lined with kitchen paper, season generously with sea salt and toss with chopped parsley and tarragon. Keep warm in a low heated oven.

For the aioli: place the egg yolks, grated garlic, Dijon mustard and a pinch of sea salt in a bowl. You can keep the bowl in place & steady by using a damp kitchen towel wrapped around the base. Whisking continuously, add the oil to the egg mixture a few drops at a time and then gradually pour a steady steam. Don’t add the oil too fast and ensure it’s completely incorporated before adding more.

Whisk until completely emulsified, then whisk in the lemon juice and season generously to taste. (Any leftovers will keep well in a jar in the fridge for up to 2 days).

Once the steak is finished in the oven, remove and allow it to sit until you are ready to sear. Heat the oil in a heavy based pan over a high heat and add the steak to cook for almost a minute or until nicely browned before flipping and adding the butter, garlic and rosemary to the pan.

Tip the pan and using a spoon, baste the steak continuously for another minute.

Remove the steak from the pan, before slicing.

Serve immediately with chips and aioli.