Limaçons are thumbnail-size snails gathered on the wild fennel by roadsides. They are laborious to prepare, like all snails, being first fed on fennel & flour for 10-12 days to clean them, then washed in running water until they stop frothing, & finally boiled in a broth of fennel, orange & garlic for 3-4 hours. If this seems like a hard fortnight’s work for the end result, look for Giselle, in the Avenue du Prado market, the last of a long line of limaçon - sellers in Marseilles. She will sell you a ladleful of her cooked speciality straight from the pot, just as her predecessors did all over Provence.