Place mushrooms in bowl; pour hot water over to cover. Let stand until mushrooms are soft, about 30 minutes. Drain. Cut off stems; discard. Slice mushroom caps; transfer to 6-quart slow cooker. Sprinkle beef with salt and pepper. Heat 1 teaspoon oil in medium nonstick skillet over medium-high heat. Add beef; cook 4 minutes per side. Transfer to slow cooker. Add remaining oil to same skillet. Add leeks, parsnips, celery, and garlic; sauté 5 minutes. Transfer mixture to slow cooker. Stir in 7 cups hot water, tomatoes with juice, barley, 1 teaspoon salt, and 1/4 teaspoon pepper. Cover; cook on high until meat falls off bone and barley is tender, about 4 1/2 hours. Remove meat from slow cooker; cool slightly. Discard bone and fat. Shred meat; return to slow cooker. Add green beans. Cover; cook until beans are tender, about 20 minutes. Season with salt and pepper. Ladle soup into bowls and serve. Makes 6 main-course servings. Per serving: calories, 216; total fat, 5 g; saturated fat, 1 g; cholesterol, 18 mg; fiber, 7 g Bon Appétit March 2004 Cooking for Health