Beans & Legumes
Legumes were domesticated alongside the first cereals, and separately on every continent that had them: lentils and chickpeas in the Fertile Crescent, soy in China, the common bean in Mesoamerica, cowpeas in West Africa. They store for years, return nitrogen to the soil, and supply the protein a grain diet lacks — which is why grain and bean travel together in nearly every traditional cuisine.