Trim excess fat from around steak and season with salt and pepper. With the edge of a heavy saucer or a meat mallet pound flour into both sides of steak. Cut into serving size pieces.
In a large skillet heat oil over medium-high heat; add steak and brown well on both sides. Remove steak to a plate and set aside.
In same skillet saute onion, celery and garlic until slightly softened. Add mushrooms and cook for 1 minute. Stir in tomatoes, basil, oregano, thyme, salt, pepper, and Worcestershire sauce; mix well.
Return steak to skillet, distributing sauce evenly over all. Bring to a boil, reduce heat and simmer over low heat, covered for 1 ½ hours, or until steak is fork tender.