Mix garlic, thyme, mint, grated red onion and yoghurt together in a large bowl. Coat lamb in yoghurt mix, cover with cling wrap and marinate overnight
Toss red peppers, onions, potatoes and garlic in a large bowl with 150ml olive oil. Season with salt, pepper and paprika and place on a hot barbecue plate. Cook until vegetables are tender, turning frequently and adjusting heat as required to prevent vegetables from burning.
Season lamb with a little salt and pepper, drizzle with remaining olive oil and cook on a hot barbecue grill or plate for 5-7 minutes before turning and cooking for a further 3 minutes until medium-rare to medium. Remove from heat and allow to rest.
Carve lamb and serve with charred vegetables and a generous drizzle of pomegranate molasses.