Turn your oven to 180C (350F).

Sprinkle lamb with chilli, if using, and a good few pinches of sea salt flakes. Wrap lamb in two layers foil, sealing well. Place on a roasting tray.

Pop lamb in the oven and set your timer for 1 hour.

After the first hour, reduce the heat to 150C (300F). Continue to cook for another 4 hours or longer until the lamb is so tender you can cut it with a spoon (literally). You can cool and refrigerate.

Remove foil from the lamb and cook at 180C (350F) to brown. Carve and serve warm.