In I think 2004, or maybe ought-three, I was working on a book about Rome for Williams-Sonoma. They wanted a baked pasta and the first thing that came into my head was bechamel-mushrooms-prosciutto-peas, why I don't know. Then I said, oh no that's too retro, but by then they had said they loved the idea and I was stuck. So I made the recipe, to the letter, to test it, for New Year's and watched, incredulous, as our guests inhaled it. Evidently retro is good. The following year, I started to assemble the ingredients for the recipe when I realized I was not testing a recipe and could use that old bag of my own spinach instead of going to the supermarket for Findus peas. From there it was a short step to mystery cheese, and I've never looked back.