In a large plastic bag, combine 1/2 cup flour, 1 teaspoon salt, 1/2 teaspoon pepper and garlic salt. Add beef, a few pieces at a time, and shake to coat. Remove meat from bag and pound with a mallet to tenderize.
In a Dutch oven, brown meat in oil until no longer pink. Add the green pepper, celery and onions; cook and stir for 10 minutes. Add garlic; cook 1 minute longer. Stir in the tomatoes, broth, soy sauce and remaining salt and pepper. Cover and bake at 325° for 2 hours.
Remove from the oven and return to stovetop. In a small bowl, combine water and remaining flour until smooth; gradually stir into juices. Bring to a boil over medium heat. Cook and stir sauce for 2 minutes or until thickened.