Ingredients

• 1 large leek (white and pale green parts only), halved lengthwise
• 5 carrots, quartered
• 1 head garlic, separated into cloves and peeled
• 2 red bell peppers, quartered
• 1 pound plum tomatoes, halved
• 1 fennel bulb, stalks discarded and bulb quartered
• 2 large onions, quartered
• 2 tablespoons olive oil
• 1 cup boiling water
• 1/2 ounce dried porcini mushrooms (1 cup)
• 1 (4-inch) piece celery
• 4 parsley stems
• 1 large thyme sprig
• 8 black peppercorns
• 2 Turkish bay leaves or 1 California
• 1 cup dry red wine
• 4 quart water
• 1/2 cup sun-dried tomatoes (not packed in oil; 1 1/2 ounces)
• 1/2 stick unsalted butter
• 1/3 cup all-purpose flour
• Equipment: cheesecloth; kitchen string
• kitchen string

Instructions

1. Preheat oven to 450°F with rack in middle.
2. Wash leek halves and pat dry.
3. Toss leek, carrots, garlic, bell peppers, plum tomatoes, fennel, and onions with oil, then spread in a 17- by 14-inch roasting pan and roast, stirring occasionally, until well browned and tender, 1 1/4 to 1 1/2 hours.
4. Soak porcini and make bouquet garni while vegetables roast: Pour boiling water over porcini in a bowl and soak until softened, 10 to 20 minutes. Meanwhile, wrap celery, parsley stems, thyme sprig, peppercorns, and bay leaves in a piece of cheesecloth and tie with string. Lift out porcini, squeezing excess liquid back into bowl, and rinse to remove any grit. Pour soaking liquid through a sieve lined with a dampened paper towel into another bowl.
5. Pour boiling water over porcini in a bowl and soak until softened, 10 to 20 minutes.
6. Meanwhile, wrap celery, parsley stems, thyme sprig, peppercorns, and bay leaves in a piece of cheesecloth and tie with string.
7. Lift out porcini, squeezing excess liquid back into bowl, and rinse to remove any grit. Pour soaking liquid through a sieve lined with a dampened paper towel into another bowl.
8. Make stock: Transfer roasted vegetables to a 6- to 8-quart pot and add wine to roasting pan, then deglaze pan by boiling, scraping up brown bits, 1 to 2 minutes. Add wine to vegetables in pot along with water (4 quarts), porcini and soaking liquid, bouquet garni, sun-dried tomatoes, and 2 teaspoons salt. Bring to a boil, then simmer, uncovered, until stock is reduced to about 6 cups, about 2 hours. Pour through a fine-mesh sieve into a large bowl, pressing firmly on and then discarding solids.
9. Transfer roasted vegetables to a 6- to 8-quart pot and add wine to roasting pan, then deglaze pan by boiling, scraping up brown bits, 1 to 2 minutes. Add wine to vegetables in pot along with water (4 quarts), porcini and soaking liquid, bouquet garni, sun-dried tomatoes, and 2 teaspoons salt. Bring to a boil, then simmer, uncovered, until stock is reduced to about 6 cups, about 2 hours. Pour through a fine-mesh sieve into a large bowl, pressing firmly on and then discarding solids.
10. Make sauce: Melt butter in a 3-quart heavy saucepan over medium heat and whisk in flour, then cook roux, whisking, 3 minutes. Add stock in a stream, whisking constantly to prevent lumps, then bring to a boil, whisking. Reduce heat and simmer, whisking occasionally, until slightly thickened, about 10 minutes. Season with salt and pepper.
11. Melt butter in a 3-quart heavy saucepan over medium heat and whisk in flour, then cook roux, whisking, 3 minutes. Add stock in a stream, whisking constantly to prevent lumps, then bring to a boil, whisking. Reduce heat and simmer, whisking occasionally, until slightly thickened, about 10 minutes. Season with salt and pepper.