A simple combination of fresh fennel, canned beans, and canned tomatoes, this stew can be turned into a complete meal by serving it with pasta, rice, polenta, or garlic bread. It can also be the base for a simple fish or shellfish meal. Just put a few white fish fillets or a pound of shrimp, clams, or mussels on top of the stew when it has just about finished cooking, cover, and simmer until cooked through. Lovely!