Fennel seeds in the tomato sauce boost the flavor of the sliced fennel bulb in this satisfying dish. A thin layer of fontina cheese on top bakes to a golden brown. For a spicy version, use hot Italian sausages rather than mild.
More often than not, red wine is best with sausage, but the relative delicacy of this delicious dish will shine through better with a crisp, herbal-flavored white wine, such as an inexpensive white Bordeaux from France.