Once upon a time, there was an easy roast chicken recipe, handed down by a fashion editor at Glamour magazine to her assistant, who was in search of a dish to prepare for dinner with her boyfriend. She made the chicken. Her boyfriend loved it. He had seconds. And shortly thereafter, he proposed. But that's not all: Three more young women at the magazine made the chicken for the men in their lives who then, in short order, popped the question. Glamour published the recipe-dubbing it, naturally, Engagement Chicken-and since then, the magazine's editors have heard from more...