Preheat the oven to 200C, 400F, Gas Mark 6.
Heat the redcurrant jelly in a small saucepan or microwave. Place the lamb on a baking tray, season with salt and black pepper and baste with the redcurrant jelly.
Roast in the oven for 20-30 minutes depending on the thickness of the lamb. Remove from the oven, cover with foil and allow to rest for 10 minutes.
Meanwhile, bring the vegetable stock to the boil and add the spices. Stir in the couscous, then remove from the heat and cover with a lid. Leave to steam for 1 minute, then fluff up the grains with a fork and add the lemon zest and juice.
Stir in the chopped mint and pile onto a serving plate.
Carve the lamb by cutting inbetween the bones and arrange on the couscous. Garnish with fresh mint and serve with vegetables.