Season the lamb with 1/2 teaspoon of the salt and 1/4 teaspoon of the black pepper and dust with 1 tablespoon of the flour. Heat the olive oil in a large, heavy deep pot or Dutch oven over medium-high heat. Add the shanks and cook, turning to brown evenly, about 10 minutes.
Add the onions, celery, carrots, the remaining 1/2 teaspoon salt, and the remaining 1/2 teaspoon black pepper and cook for 2 minutes. Add the thyme, bay leaves, and tomato paste, stirring to mix. Cook for 2 minutes, then add the beef broth and stir to mix. Bring to a boil, reduce the heat to medium, cover, and cook until the meat is very tender, about 1 1/2 hours.
Add the potatoes, turnip, and parsnips and cook, uncovered, until the vegetables are fork-tender, about 30 minutes. Dissolve the remaining 2 tablespoons flour in the water and add to the stew, stirring to blend. Simmer for 30 minutes. Remove from the heat. Using a fork, remove the meat from the bones and discard the bones. Remove the bay leaves.
Serve the stew in deep bowls and accompany with Irish Soda Bread.
Yield: 8 servings