If marron are unavailable, substitute with lobsters or yabbies.
Where to buy truffles
You can buy Australian truffles direct from the producers - ask for Al Blakers, of Manjimup Truffles, at the Five Acre Nursery, (08 9771 2258), or get in touch with fellow West Australians The Wine & Truffle Company (www.wineandtruffle.com.au), or Duncan Garvey at Tasmania's Perigord truffles (www.perigord.com.au). Otherwise Simon Johnson stores around the country have WA truffles in stock, as does Brisbane's Black Pearl Epicure, and other smaller premium retailers. If the idea of entering into a truffle co-op appeals but you can't find like-minded fellows, ask suppliers and delis; some - such as Sydney's Black Bull Butchery, in Potts Point - organise their own co-ops, and sell to their customers by the gram.