Nia Vardalos and Lainie Kazan in My Big Fat Greek WeddingMY BIG FAT GREEK WEDDING

In the first 20 minutes of the romantic comedy My Big Fat Greek Wedding, there's a scene so simple it feels revelatory. Our heroine, Toula (Nia Vardalos), is a 30-year-old waitress in a diner owned by her Greek-with-a-vengeance parents, and has always been, as she describes herself, "a frump" - plain, bespectacled, overweight, and sadly single.