I don’t know why I overlook the humble lentil. These tiny legumes that resemble pancaked pebbles are often bypassed in my pantry, as I reach for grains and beans. When I finally do cook lentils, I remember how good they taste, how satisfying they are to eat, and how easy they are to prepare. Eminently flexible, lentils can stand in for a grain, starch, even a protein. They are healthy, too—rich in nutrients and high in protein, iron, and fiber, arguably placing them neck and neck with other lauded foods in the super-food department. They also have the added benefit of being very easy on the wallet. Lentils cook quickly and without any fuss, gamely absorbing the flavors and seasonings of their fellow ingredients and braising liquids, while adding a hearty, earthy, and rich base to soups, stews, side dishes, even salads. This soup is a perfect example. It’s the …