When we were shooting the photos for my last book, Dorie’s Cookies, lunch was a highlight of the day, as each of us took turns cooking. One morning, Claudia Ficca, the food stylist, announced that she’d bought some salmon and had an idea for lunch: salmon burgers. Like everything Claudia does, these are special. They get a supersized helping of zip from lemons, capers, two kinds of mustard, scallions, lots of dill and Greek yogurt, which adds tang and, most important, moisture.