Arrange meat in bottom of a 3-quart casserole; layer potatoes, corn, tomatoes, carrots, onion, green pepper, and green beans on top of meat. Sprinkle with 1 teaspoon salt and pepper; pour 3 cups water over mixture. Cover and bake at 400° until bubbly; reduce heat to 325°, and continue to bake an additional 2 hours.
Transfer meat and vegetables to a large serving bowl or tureen using a slotted spoon; reserve liquid in casserole. Combine remaining water and flour, stirring to make a paste; add flour mixture, remaining salt, garlic powder, Worcestershire sauce, and parsley to casserole, mixing well. Cook over medium heat, stirring constantly, until gravy thickens.
Spoon gravy over vegetable-meat mixture; serve hot.