This is a hearty soup called sopa coada (“smothering soup”) from the Treviso region north of Venice. It is traditionally cooked in a clay pot glazed on all sides except the bottom. Italian home cooks use pigeon, squab, or wild ducks shot in the marshes as so beautifully described in Ernest Hemingway’s Across the River and into the Trees.
I’ve made this dish many times with a pair of legs from a domestic duck and have always had excellent results. The soup is usually made with a pigeon that is cleaned, sautéed in butter, and stewed in a white wine–flavored broth; it is served with thick, finger-long pieces of hearty bread that have been buttered, covered with cheese, and lightly baked.
There are two ways of making this soup: the modern way, as described here, and the traditional way, which allows the soup to “brood” for five or more hours in a 250°F oven.
If you can’t find good, sturdy country-style bread, you can make your own. If you do so, be sure to bake the loaf about three to four days in advance, slice the bread, and allow it to dry partially as directed in the recipe.