1. Marinate the lamb overnight in the mint sauce.
2. Pre-heat the oven to 190C/375F/gas mark 5. Place the lamb in the roasting tin and pour over the vegetable stock. Place the garlic next to the lamb and cover the roasting tin with foil. Place in the oven for about one hour if you like your meat pink; if not, cook for slightly longer.
3. Take the meat out of the roasting tin, leave to rest and then place the tin with the meat juice over a medium heat to make the gravy. Add the flour to the pan of meat juice and stir in the red wine. Add the redcurrent jelly and whisk until the jelly has dissolved. Taste and season as necessary.