In a shallow dish,combine the flour,1/2 tsp salt,and the black pepper. Roll beef in flour mixture,coating completely. In a soup pot,heat 3 tablespoons oil over high heat until hot. Brown beef on all sides for 5 minutes.
Remove beef from pot. Set aside. Add mushrooms,bell pepper,onion,garlic,and remaining 1 tbsp oil to pot,and cook 5 minutes,or until onions are tender,stirring occasionally.
Add remaining ingredients, including remaining 1/2 teaspoon salt; return beef to pot and bring to a boil. Reduce heat to low and simmer 1-1/2-2 hours,or until beef is fork-tender, stirring occasionally.