Preheat oven to 425°.
Heat oil in a large nonstick skillet over medium-high heat. Add carrot, fennel, onion, and garlic; sauté 5 minutes. Spoon carrot mixture into an 11 x 7-inch baking dish. Stir in beans and next 5 ingredients (beans through pepper).
Trim crusts from bread. Cut bread into 1-inch cubes. Lightly coat cubes with cooking spray. Arrange bread cubes in a single layer over carrot mixture pressing cubes gently into mixture. Cover mixture with foil, and bake at 425° for 25 minutes. Uncover and bake an additional 5 minutes or until croutons are golden brown. Garnish cassoulet with sage leaves, if desired.