Creamy Cremini Mushroom Soup

Ingredients

• 1 3 pound chicken, (or use parts, such as wings and backs)
• 4 stalks celery, (with leaves), trimmed and cut into 2-inch pieces
• 4 medium carrots, peeled and cut into 2-inch pieces
• 1 medium onion, peeled and quartered
• 6 clove garlic, peeled
• 1 small bunch fresh parsley, washed
• 6 sprigs fresh thyme, or 1 teaspoon dried
• 1 tsp kosher salt, or, to taste
• 4 quarts water
• 1 1/2 tsp extra-virgin olive oil
• 1 large onion, chopped
• 1 1/2 tsp chopped fresh thyme, or 1/2 teaspoon dried
• 1 lb cremini mushrooms, sliced
• 1/2 cup all-purpose flour
• 3 1/2 cup Homemade Chicken Broth or 2 (14-ounce) cans reduced-sodium chicken broth
• 1 cup reduced-fat sour cream
• 1 cup low-fat milk
• Salt & freshly ground pepper, to taste
• Lemon juice, to taste
• Dry sherry, to taste (optional; see Note)

Instructions

1. To prepare both: Combine chicken, celery, carrots, onion, garlic, parsley, thyme, salt and water in a large stockpot and bring to a boil over medium-high heat. Reduce heat to medium-low and simmer, partially covered, until the chicken is falling apart, about 2 hours. Skim the foam from the surface as it builds up.
2. Strain the broth through a large sieve or colander into a large bowl. Use a wooden spoon to press on the solids to extract as much of the broth as possible. Divide the broth among several shallow containers so it will cool quickly. Cover loosely and refrigerate overnight. Use a spoon to remove the fat that congeals on the surface.
3. To prepare soup: Heat oil in a Dutch oven or soup pot over low heat. Add onion and cook, stirring until soft and translucent, 5 to 7 minutes. Add thyme and cook for 1 minute more. Stir in mushrooms, cover pot and steam until the mushrooms exude their moisture, about 5 minutes.
4. Sprinkle flour over the mushrooms. Increase heat to medium and cook, stirring, for 3 to 4 minutes. Gradually whisk in broth, scraping up any flour that clings to the pan. Simmer, stirring occasionally, until thickened and smooth, 5 to 7 minutes.
5. Combine sour cream and milk; whisk into the mushrooms. Season with salt and pepper. Gently heat until the soup is hot but not boiling. Just before serving, stir in lemon juice and sherry (if using).