Heat the oven to 150C/130C fan/gas 2 or set the slow cooker to low. If the pork is tied, remove the string. Rub the spice blend all over. Season. Put the pork in a large flameproof casserole or the slow cooker, and sprinkle over any remaining spice blend and the bay leaves. Pour in a mugful of water, cover with the lid and cook for 5-7 hrs, or until the pork can be shredded with a fork.

Lift the pork onto a plate. Remove and discard any skin and fat. Shred the meat using two forks, discarding any sinew. Put the casserole over a medium heat (or pour the liquid into a saucepan). Add the vinegar, sugar and barbecue sauce. Simmer until the liquid has reduced and is glossy, about 15-20 mins.

Mix the meat through the sauce. Serve in buns or over jacket potatoes. Once cooled, keeps chilled for 48 hrs or frozen for three months.