Bon appétit is an expression, directly translated as "good appetite" and used as a courtesy at the beginning of a meal. When we were newly married and living in Boston we had a flat with lovely parquet floors but practically no furniture. Our bed was a mattress like a small island on this acreage of shining wood. On Saturday mornings we lay in bed and watched Julia Child talking passionately about food and chucking saucepans over her shoulder. She invariably signed off with a determined "Bon appétit ".