For a while, this documentary about the legendary restaurant outside Barcelona may drive you a little batty. The dishes, invented in a lab kitchen by scientist-chefs, are such avant-garde creations — veal marrow with beet foam, anyone? Ice-chip vinaigrette? — that they don’t make you hungry. They make you want to see a marathon of Diners, Drive-ins and Dives. Yet as we get to know the dishes, El Bulli becomes a haunting celebration of the human desire to turn food into art — even if the results are consciously insane. A?