In south-west France, black truffles are big business, with special markets set-up in season to sell the truffles to buyers from the grand restaurants. But they are also rather expensive. Luckily it is possible to buy small quantities of preserved truffles in jars or tins that, while still expensive, are an affordable treat. I can't really describe the flavour very well, but I recommend you try it - they have quite a 'rich' taste.
Truffle omelette is common in restaurants across much of the South of France. Unfortunately these are very often a disappointment, even in reasonably expensive restaurants. Certainly a very common complaint is 'I paid 15 euros for a truffle omelette but I couldn't taste the truffles'.
Recipe for truffle omelette
One truffle is enough for four people. The truffle (fresh or preserved) should be soaked in brandy or cognac for a few hours or preferably overnight, before use. Preserved truffle needs less soaking time than fresh truffle, but still needs at least an hour.
Peel and very thinly slice the truffle.
Beat four eggs with plenty of freshly-milled pepper, and a small dash of cream (1/5th of a cup full is plenty). Preferably, you will only add salt at the time of serving / eating rather than as part of the cooking, but this is not critical.
Fry the omelette gently. Butter is fine for this, but if you have some goose fat to hand that will be even better.
When the omelette is just starting to set, sprinkle over the truffle slices.
Serve with a little bit of salad, and try to stop your children pouring tomato ketchup on top.