"The Chester Square Cookery School in the heart of London offers students a refined setting in which to master the fine art of choux pastry and hone their hollandaise. True, the ornate mansion doesn't quite sparkle the way it used to--a feeling chef Paul Delamare is familiar with these days. Worn out and newly broke, he'd be tempted to turn down the request to fill in as teacher for a week-long residential course, if anyone other than Christian Wagner...