Remove the meat from the fridge 30 minutes before cooking.
Dry roast the pistachio nuts briefly in a non-stick frying pan.
Put the rocket into a blender; add the pistachio nuts and the cheese, olive oil and salt and pepper. Blend until you have a chunky pesto sauce.
Heat up the griddle (non-stick frying pan or barbecue). Brush the steaks with the remaining oil. Place on the hot griddle and cook for 3-4 minutes on each side until cooked to your liking. Leave to rest for 2 minutes.
Place a small spoonful of pesto on each of the lamb steaks and serve the rest of the pesto separately. Serve with halved grilled tomatoes and fresh pasta.
Don’t blend your pesto too much; the small pieces of pistachio nut will add a fabulous crunchy texture that is very different from ready-made pesto sauces.