This cover image released by Knopf shows “Wafu Cooking: Everyday Recipes with Japanese Style,” a cookbook by Sonoko Sakai. (Knopf via AP) By ALBERT STUMM When Sonoko Sakai’s mother snuck a little miso into her lasagna, she wasn’t thinking of the kind of Japanese fusion that became an American dining craze in the 1980s. Rather, she was doing what Japanese cooks had been doing for centuries, adapting to outside influences.