For at least a generation, food writers have been discovering grains and beans as nourishing fare that’s easy on the planet, & purse, and arteries. About 10 years ago the Londons assembled a collection of nutritionally correct recipes with a whole-grain base. This time their approach is more ecumenical. Red meat and white rice coexist with vegetarian entries and alternative grains; ethnic dishes mix with cross-cultural combinations; and bolder accents of hot and pungent flavors perk up featured staples. With The Versatile Grain and the Elegant Bean, more than 300 recipes for dozens of beans and grains, the Londons surely make their case for versatility. B