THE French, self-appointed masters of the Western world's culinary as well as amorous arts, have a saying: if a woman is still only a girlfriend, give her roses; if she's already your mistress, give her the heart of a lettuce. Very romantic.
The fact is that the white-coloured sap of the common or garden lettuce is considered, by the French, to be an aphrodisiac. Actually, they might well be wrong. Since Babylonian times it has been known to have mild narcotic qualities, having a molecular structure akin to opium. Indeed, the medication laudanum, a fashionable drug among 19th century English intellectuals, was distilled from lettuce sap. But anyone who, out of curiosity, has ever licked the stem of a freshly cut lettuce to see how its dripping milk tastes, is unlikely to do it again. It's about as bitter as eating dandelions, to which it is related.
Not that you will ever get much chance of tasting a freshly cut lettuce in Hong Kong. The choice here is between the mass grown iceberg, hard as a Malay rattan ball and about as tasty, and the many-coloured designer leaves that lie limply on the frosty shelves of the smart food stores, as if exhausted from the journey that brought them here.
Choosing a lettuce for the French is like a Cantonese picking out a live fish from a tank. The French aristocrats of old, before they themselves succumbed to the fall of the knife on their spinal stem, would keep discerning rabbits to sample the green leaves.
Although the bitter sap of the lettuce is considered to be good for the liver, the Frenchman's most precious organ, there prevails a great misunderstanding in the Anglo-American world that the purpose of eating lettuce is to promote health, and the more you eat the healthier you will be. For the French, never a group to let health get in the way of sensuality, the humble vegetable takes on the allure of eroticism. Perhaps that's why Americans eat a salad as the starter to a meal while in France it comes dripping with the simplest of all dressing, a plain old-fashioned vinaigrette, after the main course.
In Hong Kong it is virtually impossible to buy a lettuce with any real flavour; the salad world has been taken over by an assortment of trendy leaves, each flabbier and more expensive than the last with names like frise, red batava, lolorossa and mache. Taste and texture, it seems, have been sacrificed to convenience. Today's lettuces are too cosseted: they are grown in tunnels under polythene in a nutrient solution designed to make them grow as fast as possible.
There are four main kinds, each of which has several varieties: the round or butterhead; crisp lettuces such as iceberg; cos or romaine; and loose leaf.