The French have fought a losing battle with the vineyards of California and suffered the indignity of having their elegant pommes frites renamed "Freedom Fries". Now they face a new challenge from America over their most highly-prized and aromatic delicacy. Just a few miles from the birthplace of frontier pioneer Davy Crockett, mushroom expert Tom Michaels has unlocked the secret of commercial production of the famous Périgord black truffle. In a breakthrough that could one day make an American-grown Périgord truffle as ubiquitous worldwide as the Big Mac, Mr Michaels has produced his first crop of the pungent nodules in...