Cut cubed steaks into large serving pieces. Mix together salt, pepper and garlic powder. Season steaks on both sides.
Dredge steaks through the flour. Shake off excess flour. Heat 1/3 cup cooking oil in large skillet.
Brown steak pieces on both sides in the oil. Remove to a clean platter. Turn heat to medium in the same skillet.
To the warm skillet, add minced garlic, onions and can of diced tomatoes. Mash the tomatoes, slighty, with a fork. Add the onion soup mix and water. Stir to combine. Add browned steak pieces along with any juices back to the skillet. Stir to coat the meat with tomato mixture. Cover and lower heat to low.
Simmer the steaks on low for 1 and 1/2 hours stirring frequently.
Season with more salt and pepper if desired. Serve with rice, mashed potatoes or noodles.