Oysters are popular at Christmas time, but many Australian varieties spawn at this time of year, making them fragile and creamy, so it's best to go with rock varieties, which are still in season. Make sure you buy them freshly shucked. If they're being shucked for you at your fish market, ask that they be washed only minimally so they lose as little juice as possible and retain their lovely briny flavour.
Note Panko crumbs, or Japanese breadcrumbs, are available from Japanese grocers. If they're unavailable, substitute dried breadcrumbs. XO sauce is available from Asian grocers.