Place joint, fat side uppermost, on a board (remove strings if it's strung) and open out. Carefully score the rind deeply, turn over the joint and cut into 4 equal-ish size chunks. Use 2 metal skewers per chunk and skewer through at angles (do this just before cooking if it's easier). Place in a dish fat side uppermost. Add all remaining ingredients and move chunks around in the mixture to coat. Cover and place in fridge for 3-4 hours (if you have time) to allow flavours to absorb. Meanwhile heat the BBQ make sure the coals are hot and ?grey' before you start cooking. Alternatively if it starts to rain preheat the oven and cook directly on a preheated oven shelf but put a ?drip tray' on the next shelf under the joint. Cook for about 75 minutes until rind is crispy and golden, and meat juicy but cooked through. If the outside of the meat starts to catch cover with foil. If you don't have a kettle or lidded BBQ, cover the joint with a foil container to create a lid. Cover but keep turning and adjust the grid height to move away from the heat if it is cooking too quickly. Allow to rest for 10-15 minutes and then serve one chunk between two, cut in chunky slices to serve. Serve with crushed new potatoes topped with lemon rind, crushed garlic, chopped fresh dill and a couple of spoonfuls of mayo.