Moroccan Spiced Lamb with Beetroot

Preheat the oven to 190°C. Wrap the beetroot in foil and place in a baking dish. Bake until tender (small ones will take 30-40 mins; larger up to 2 hours - test with a knife). Remove from the oven and leave until cool enough to handle, then rub off the skins. Roughly chop, then blitz in a food processor with the yoghurt, seasoning to taste. Mix the oil, lemon zest and juice, garlic and spices in a bowl. Add the lamb and toss together. If you have time, marinate in the fridge for an hour or two. Put the couscous in a large bowl and add just enough boiling water to cover. Pop in the butter, stir and leave to absorb for about 10 mins. Fluff it up with a fork. Add the lemon zest, juice, herbs and stir. Heat a griddle pan until very hot. Cook the lamb on both sides for 3-4 mins, depending on thickness. Rest the meat for 5 mins, then serve with the couscous and a dollop of beetroot purée (warm it in a pan if you like).