- Blitz the marinade ingredients in a food processor until you achieve a fine paste. Season with salt and pepper. Rub the paste all over the lamb, making sure to really work it into the flesh, then place the lamb in a roasting tray and leave to marinate in the fridge overnight.
- When you’re ready to cook the lamb, preheat the oven to 200˚C. Season the lamb with a little more salt and pepper, then roast in the oven for 1 hour, until golden brown all over. (This will result in lamb that is a little pink in the middle; if you like it more well done, then cook for a further 30 minutes.).
- To make the tzatziki, mix together all the ingredients in a small bowl and leave in the fridge until needed.
- When the lamb is cooked, remove it from the oven and leave it to rest, covered in foil, for 15 minutes before carving. Serve with a generous dollop of tzatziki.