Make 2 or 3 slits on the surface of the lamb, and insert garlic slices. Combine ginger and mustard and rub over surface of lamb. Bake in a moderate oven (180 deg C, 355 deg F) for 1 hr. Dissolve sugar in the coffee, stir in the cream and port, pour over the lamb. Bake a further 45 minutes, for the lamb to be a little pink near the bone, 1 1/4 hours for well done lamb, basting occasionally. Lift the lamb onto a serving platter and keep warm. Skim the fat from the pan juices and reserve. Add water to the meat juices to make 1.5 cups, and set aside. Put 2 tablespoons of the reserved fat into the roasting dish, stir in the flour and cook for 2 minutes. Gradually add pan juices, stirring constantly. Cook until smooth and thickened. Blend in recdurrent jelly, and cook until melted. Serve the sauce separately.

This goes very well with a good red wine.