It was just one of many points of cultural overlap for the couple, further explored in their book, “Simply West African: Easy, Joyful Recipes for Every Kitchen.” In it, the couple are in sync, with Thiam’s story and recipes augmented by Katayama’s help. But more enticing still are those moments of culinary overlap, as in a karaage-style West African fried chicken, served with moyo sauce, a vibrant relish of tomatoes, peppers and tomatoes; a dish they call “West Africa meets Japan” fonio porridge, served with umeboshi, those lovely pickled plums, and togarashi, the electric Japanese chile powder; pumpkin-peanut rice balls with maafé, a melding of their respective childhoods and a recipe developed with their 4-year-old daughter, Naia, in mind.