In a large saucepan, cook meat in 1 tablespoon butter until browned; drain and set meat aside. In same saucepan, saute the celery, onion and garlic with remaining butter until tender. Stir in the tomatoes, 3/4 cup water, salt, oregano, pepper and reserved meat. Bring to a boil. Reduce heat; cover and simmer for 1 hour.
Stir in beans and parsley. Return to a boil. Reduce heat; cover and simmer for about 30 minutes longer or until meat and beans are tender. Combine cornstarch and remaining water until smooth. Gradually stir into stew. Bring to a boil; cook and stir for 1-2 minutes or until thickened.