Combine flour, 1 teaspoon salt, and 1/2 teaspoon pepper in a plastic or paper bag; shake to mix. Place brisket cubes, a few at a time, in bag; shake well.
Cook brisket cubes in hot oil in a large Dutch oven over medium heat, stirring to brown on all sides. Add water, chopped onion, garlic, salt, and pepper. Cover and simmer 1 hour. Add remaining ingredients. Cover and simmer 1 hour and 15 minutes or until vegetables are tender.