Season lamb stew meat with salt, pepper, and garlic powder.

Place lamb in a baking pan and brown both sides under the broiler.

Combine beef broth, water, bay leaf, and browned lamb in a soup pot.

Bring to a boil, then reduce heat and simmer, covered, for 1 hour.

Remove bay leaf and lamb from the pot. Let the lamb cool slightly.

Remove the meat from the bones and discard the bones and bay leaf.

Return the meat to the pot and add celery, carrot, turnip, onion, leek, barley, and thyme.

Cover and simmer for 1 hour, or until vegetables and barley are tender.

Season with additional salt and pepper to taste.