Heat oven to 200C/fan 180C/gas 6. Put the steak on a plate and rub with 2 tbsp extra-virgin olive oil and plenty of black pepper and flaky sea salt. Leave to marinate at room temperature for about 10 mins. Heat a heavy-based ovenproof frying pan until searingly hot.
Add the meat to the pan, with oil from the plate, the garlic cloves, thyme and bay leaf. Sear the steak for 3 mins on the first side until well browned, basting with the oil and herbs as it cooks. Carefully tip off the oil, add another 2 tbsp, then sear the second side of the steak in the same way. Quickly brown around the edges, then slide the pan into the oven and roast for 15 mins, turning over halfway through.
Take the steak from the pan and sit it on a rack over a roasting tin. Tip the oil, herbs and garlic from the pan over the steak, then leave to rest for 15-20 mins. Leave the steak uncovered – covering with foil will make the steak steam and lose its crisp crust.
Meanwhile, start the hollandaise. Put a medium pan of water on to boil. Put the vinegar, basil stalks, bay leaf and spices into a small pan. Boil down to about 3 tbsp, then strain. Put the egg yolks into a large, deep bowl, add 1 tbsp cold water and 1 tbsp of the vinegar reduction, then whisk briefly until light and frothy.
Put the bowl over, but not touching, the simmering water, then whisk to a light, airy foam. Now gradually add the butter, little by little, whisking all the time to make a silky yellow sauce. Prevent the sauce overheating by lifting the bowl on and off the pan, adding a splash more water if it starts to get too thick. The sauce can be kept warm for up to 30 mins by sitting the bowl in a bath of just-warm water. If it gets too hot, the sauce will split. Just before serving, finely chop the basil and stir into the sauce with the lemon juice and seasoning to taste.
HOLLANDAISE TIP: This recipe makes enough reduction for three
batches of sauce – keep what’s left over in the
fridge for several months. We make huge batches
in our restaurants, reducing to 100ml, adding a
little water and storing in a squeezy bottle. Leftover hollandaise will keep well in the
fridge for up to 2 days. Try stirring it through some
mash to top a fish pie.