As with most stews, Navarin simply improves if it is kept overnight, or even several days. But wait to cook and add the green vegetables until the day you serve the stew. Boil, rinse and drain them a few hours ahead if you like and then add them to the stew just a couple of minutes before serving so that they don't lose their bright color.
This classic dish, with its surfeit of vegetables and associations with spring, should be served with a delicate, perfumed wine, such as a Pinot Noir. Try one from Côte de Nuits in France or, for a more reasonably priced alternative, from Santa Barbara in California.