1 bulb fennel, stalks discarded
3 red bell peppers, pierced with tip of knife
3 yellow bell peppers, pierced with tip of knife
2 medium zucchini, quartered
1 medium eggplant, quartered
About 1/2 cup extra-virgin olive oil
1 head garlic
2 cups tomato sauce
1 tablespoon fresh basil, chopped
2 teaspoons fresh thyme, chopped
2 teaspoons fresh marjoram, chopped
2 teaspoons kosher salt
1 teaspoon freshly ground black pepper
1 tablespoon balsamic vinegar
Preheat oven to 350°F.
In large saucepan over moderately high heat, bring 2 quarts salted water to boil. Add fennel and boil until tender, about 10 minutes.
Meanwhile, rub red and yellow peppers, zucchini, and eggplant with olive oil and transfer to large baking sheet. Cut off top 1/2 inch from garlic head. Wrap in foil and transfer to baking sheet alongside vegetables.
When fennel is tender, use tongs to transfer to sheet and rub with oil. Roast vegetables, turning occasionally, until tender and slightly browned, 30 to 40 minutes.
Transfer roasted peppers to large bowl and cover with plastic wrap. Let all vegetables stand until cooled slightly, about 10 minutes. Peel and deseed peppers, then finely dice. Remove seeds from zucchini and finely dice. Finely dice eggplant. Core fennel and finely dice.
In large saucepan over moderately high heat, combine diced roasted vegetables and tomato sauce. Squeeze garlic from skins into pan. Simmer mixture, uncovered, stirring occasionally, until thickened with very little liquid remaining, about 10 minutes.
Stir in basil, thyme, marjoram, salt, pepper, balsamic vinegar, and remaining 1/4 cup olive oil. Serve immediately.