Get your meat out of the fridge and up to room temperature before you cook it. Preheat the oven to 180ºC.
Drizzle the lamb racks with olive oil and sprinkle generously with sea salt and black pepper, patting the seasoning all over the meat.
Sear in a hot frying pan on a high heat with a little extra oil and 1 knob of butter for 2 to 3 minutes, turning with tongs until golden all over, then remove the racks to a roasting tray and let them cool.
Peel 2 cloves of garlic and place in a food processor with the pistachios and parsley (stalks and all). Tear in the bread, finely grate in half the nutmeg and blitz into a fine green crumb.
Generously brush each lamb rack with mustard, then cover with the herby crumb, patting it all over the top and sides.
Roast for 25 minutes, until the crust is crisp, to give you beautifully blushing lamb. Remove from the oven and leave the lamb to rest for 10 minutes.
