Navarin Printanier (Spring Lamb Stew)

A navarin, though the original calls for mutton, is excellent with flavorful lamb. The name refers to navets, or turnips, and the spring version, a navarin printanier, combines mutton with new potatoes and other young vegetables ready in the garden or market; tomato is optional at any season. Reheated the next day, the stew has lost its freshness, partl…