Creamy mushroom barley soup recipe

Ingredients

• 1/2 cup pearl barley
• 4 1/2 cups mushroom broth or reduced-sodium chicken broth divided
• 1 ounce dried porcini mushrooms
• 2 cups boiling water
• 2 teaspoons butter
• 1 tablespoon extra-virgin olive
• 1 cup minced shallots
• 8 cups sliced white mushrooms
• 2 stalks celery finely chopped
• 1 tablespoon minced fresh sage or 1 teaspoon dried
• 1/2 teaspoon salt
• 1/2 teaspoon freshly ground pepper
• 2 tablespoons all-purpose flour
• 1 cup dry-to-medium sherry
• 1/2 cup reduced-fat sour cream
• 1/4 cup minced fresh chives