Castelluccio lentils with tomatoes and Gorgonzola

Castelluccio lentils from Umbria are tiny brownish jewels with a delicate flavour and a wonderfully tender texture. Like Puy lentils, they don’t disintegrate in the cooking, which makes them ideal for salads. You can get them from some Italian delis, or use Puy instead. This substantial dish, which is best eaten at room temperature, can be served on its own or with steamed seasonal greens such as broccolini or baby fennel.