Spread bread cubes in a large shallow roasting pan. Bake in a 300 degrees F oven for 10 to 15 minutes or until bread cubes are dry, stirring twice. Cool. Increase oven to 325 degrees F.
Remove green leafy tops from fennel; snip enough of the tops to make 1 to 2 tablespoons. Set aside. Cut off and discard upper stalks. Remove any wilted outer layers and cut a thin slice from the fennel base. Cut fennel bulb into wedges, removing the core. Coarsely chop fennel.
In a large skillet cook chopped fennel bulb, carrot, onion, and garlic in hot oil over medium heat until tender, stirring occasionally. Stir in snipped fennel tops, Italian seasoning, pepper, and salt. Place fennel mixture in a very large bowl. Stir in bread cubes. Drizzle with enough broth to moisten; toss gently to coat. Transfer mixture to a 2-quart casserole. Bake, covered, in the 325 degrees F oven for 20 minutes. Uncover; bake about 20 minutes more or until heated through. Makes 12 to 14 servings.