Many cultures have a lentil soup as part of their culinary repertoire – the comforting way they thicken and enrich a broth has endeared them to cooks from Colombo to Casablanca, and farther afield, too. The local version below has warmed my stomach, and my heart, on many a wet walk or chilly cycle ride, often bolstered by a scone or a buttered bannock – soup is still taken seriously in Scotland, where you rarely find a cafe that doesn’t offer at least one example. The lentil variety is an old favourite that, you complicate “at your peril”, as Tom Morton explains in Shetland: Cooking on the Edge of the World (the book he wrote with his son James. as well as the island where I enjoyed an excellent bowl last autumn).. “Keep it simple.” But what’s the best way to do so?