Roasted Vegetable Soup

• 3 to 4 cups chicken stock, preferably homemade, recipe follows
• 1 quart Roasted Winter Vegetables, recipe follows
• Kosher salt and freshly ground black pepper

Chicken Stock:

• 3 (5-pound) roasting chickens
• 3 large yellow onions, unpeeled, quartered
• 6 carrots, unpeeled, halved
• 4 celery stalks with leaves, cut in thirds
• 4 parsnips, unpeeled, cut in 1/2, optional
• 20 sprigs fresh parsley
• 15 sprigs fresh thyme
• 20 sprigs fresh dill
• 1 head garlic, unpeeled, cut in 1/2 crosswise
• 2 tablespoons kosher salt
• 2 teaspoons whole black peppercorns

Roasted Winter Vegetables:

• 1 pound carrots, peeled
• 1 pound parsnips, peeled
• 1 large sweet potato, peeled
• 1 small butternut squash (about 2 pounds), peeled and seeded
• 3 tablespoons good olive oil
• 1 1/2 teaspoons kosher salt
• 1/2 teaspoon freshly ground black pepper 
• 2 tablespoons chopped fresh flat-leaf parsley