1. Place all the ingredients for the salsa verde in a mini chopper/food processor and blitz until fairly smooth.
2. For the steak, heat a dry cast-iron or stainless steel frying pan on a high heat until hot. Smear the steaks with oil on each side and season with salt and black pepper. When the pan is very hot add ½ tablespoon of oil and quickly add the steaks. Fry for 2 minutes on each side for rare. Do not move the steaks in the pan as soon as you put them in otherwise they will stick – let them form a crust first and then you’ll be able to turn them over when browned.
3. Once the steak is cooked to your liking, remove from the pan onto a warm plate, and cover with foil and a couple of tea towels to keep warm. Leave to rest for 5-10 minutes. Serve with a little of the salsa verde sauce.