In 1977, food writer Mollie Katzen published The Moosewood Cookbook, a collection of plant-focused recipes in a time when vegetables were often just garnishes and sides. The book is largely credited with helping bring vegetables to center stage. Eleven cookbooks later, and with a new one out this month, Katzen says she's cooking lighter, spicier, more relaxed recipes. She talks to Joy Cardin about cooking with vegetables for a newer generation.