Start by soaking your ham hocks in cold water. Leave them for at least four hours or overnight. This removes the extra salt from the curing process. Drain the water before you start the cooking.

Place the meat in a very large stockpot. Add the carrots, celery, onion, and the bay leaves. Cover with fresh water and bring to a boil. Simmer gently for about three hours until very soft.

Take the hot ham hocks out of the pot. Let them cool until you can touch the meat. Pull the meat away from the bone and skin. Shred it into small chunks with your clean hands.

Pour the cooking liquid through a very fine sieve. Measure out two cups of the clear golden stock. Stir in the vinegar and the soaked gelatin sheets. Whisk until the gelatin is fully dissolved and smooth.

Line your terrine mold with two layers of wrap. Leave some extra hanging over the long sides. This makes it easy to pull the terrine out. Sprinkle some chopped parsley into the bottom of the tin.

Pack the shredded pork into the lined loaf tin. Press it down firmly to avoid any air gaps. Pour the gelatin stock over the meat slowly. The liquid should just cover the top of the pork.

Fold the plastic wrap over the top of the meat. Place a heavy weight on top of the terrine. Chill in the fridge for at least twelve hours. This makes the terrine firm and easy to slice.