A romantic comedy so slight that it barely exists, My Big Fat Greek Wedding imbues a familiar Cinderella story with broad humor rooted in the sort of gregarious ethnic clan filmmakers love to contrast with stuffy WASPs. In spite of the title, the family in question has a strangely generic quality. Director Joel Zwick's follow-up to the Bronson Pinchot ESP comedy Second Sight is about Greek characters, but it could just as easily be about a Jewish, Polish, Irish, or Italian family whose colorful behavior fills its members with a curious mixture of pride and embarrassment. Making an inauspicious debut on two fronts, first-time screenwriter Nia Vardalos stars as a frustrated 30-year-old wallflower chafing under the constraints of her overbearing family, who expect nothing from her but hordes of children fathered by a proper Greek husband. Vardalos, however, has more ambitious and assimilation-minded plans, and over the course of a self-administered makeover, she morphs from a mousy, bespectacled hostess in the family restaurant to a ravishing, contact-lens-wearing college student. Empowered by her flashy new look, Vardalos wins the heart of hunky, sensitive high-school teacher John Corbett, but her family strenuously objects to the pair's inter-ethnic romance. For the sake of reciprocity, Corbett's WASPy family is drawn just as broadly as Vardalos' earthy clan, but even the inevitable culture clash is muted and underwhelming. Produced by Tom Hanks and Rita Wilson and co-starring 'N Sync heartthrob Joey Fatone, My Big Fat Greek Wedding stays unrelentingly pleasant, but affability is a poor substitute for laughs or chemistry. Zwick's film aspires to little besides winning smiles of recognition from Greeks eager to see their lives and lifestyles onscreen, but it's likely to draw shrugs of indifference from everyone else.