Dust the shanks in the seasoned flour, shaking off any excess. Heat half the oil in a heavy based pan over high heat and brown the lamb on all sides-this might need to be done in a couple of batches. Remove and set aside.
Add the remaining oil to the pan and cook the onion for a 2-3 minutes. Add the garlic, chilli, ginger and five spice and cook stirring for 1-2 minutes until fragrant.
Add the remaining ingredients, stir well and bring to the boil.
Return the lamb to the pan, reduce the ehat to low and simmer covered for 1 1/2 hours or the meat is almost falling off the bone and very tender.
Check the seasonings and skim off any excess oil.
Serve over mash (wasabi mash is good) or rice, with steamed green veg and lime wedges.