I'm a sucker for food television shows. Especially ones that feature that insatiable British domestic goddess Nigella Lawson, author of such wildly popular cookery books as "How to Be a Domestic Goddess," "Nigella Bites," "Forever Summer," and her latest opus, "Feast." It's the latter book, with its emphasis on celebratory cooking, that ties into Nigella's latest program, Nigella Feasts , which launched yesterday in the US on Food Network. To know Nigella is to love her. And to love her means giving into fat, butter, sugar, and god knows what else in pursuit of deliciously dreamy foodstuffs. If you can't handle a deep-fried Mars bar, this is not the cooking show for you. But if you've got a yearning for chocolate cherry trifle and lamb with pomegranate and feta, Nigella is the gal for you. My girlfriend, formerly hopeless in the kitchen, was transformed by Nigella's "How to Be a Domestic Goddess." Now she makes a