Preheat oven to 180°C/350°F (160°C fan).

Mix curry paste, coconut milk and stock in a 22 x 33cm / 9 x 13" baking dish, preferably glass or ceramic (Note 5). Add onion, potato, star anise, cinnamon and lamb.

Turn shanks to coat in sauce, then cover with foil.

Bake in oven for 2 hours. Remove foil, bake for a further 1 hour (small shanks) or 1.5 hrs (medium to large shanks), turning lamb twice to brown evenly, until meat is so tender it can easily be teased apart with 2 forks.

Remove lamb onto plate. Carefully skim off excess fat off the surface (tilt dish, it's easier) - I get about 1/3 cup. Mix sauce in baking dish - it should be reduced down to a syrupy thickness (Note 6).

Serve lamb with sauce over jasmine rice, garnished with chilli and coriander. For a larger banquet, put the curry out on a platter to share!