Open the shoulder of lamb out. Mix half a bottle of red wine and 35ml water, plus the star anise and coriander seeds in a dish large enough for the meat. Add the meat and leave to marinate overnight.
The next day, heat the oven to 140C. Roll the shoulder up and tie tightly with string to keep a neat tube shape. Now place the celery, onion, bay leaves and peppercorns in an oven proof dish or meat tray. Place the tied meat on top and pour over half of the marinade plus 75ml stock (chicken or lamb). Put this the oven for 2½ hours. Once cooked, take out of the liquid and leave for half an hour to cool. Remove the string and roll up with heatproof clingfilm into a tight sausage, twisting each end to make it very tight. Puncture this so that the liquid can escape, but keep it tight. Place in the fridge for a couple of hours to set. Strain the cooking liquid and place in a saucepan; this is your gravy.
When you’re ready to prepare the meal, remove the meat from the fridge and slice into 10 cm rounds. Heat the gravy and braise each piece in it to heat through, adding a few diced carrots. Use the remaining gravy to drizzle over each portion, with a few carrots and a sprinkle of parsley.
Serve on heated plates with your favourite greens and potatoes.