In 12" skillet heat oil. Season steak pieces with salt, pepper, and garlic powder. Dredge in flour until coated. Brown in hot oil. Remove and drain on paper towels.
In grease remaining in pan, saute onions, peppers, and celery until clear, but not brown. Return meat to skillet with the onions, peppers, and celery. Add tomato sauce and boiling water. Cover and put into preheated 350 degree oven. Bake until meat is tender...about 45 min.
Remove from oven, stir and test meat for tenderness. Add Kitchen Bouquet and Worchestershire sauce, stirring to combine well. Taste for salt and pepper. Return to oven covered for another 15 min. or until meat is tender.
Stir well before serving. Serve over mashed potatoes or rice.