1Using a large stock pot, brown stewing meat in oil. Add onions and sprinkle flour into stock pot, stirring until flour is well incorporated.
2Fill stock pot with water. If you prefer a thick stew fill stock pot only half full, if you prefer a more diluted stew fill your stock pot within one inch of the top. Let meat cook until tender, checking frequently on water level. When water evaporates add more. Cook for 1 1/2 hours.
3When beef is tender add potatoes, carrots and beefy mushroom soup. Cook for 30 to 45 minutes, or until tender.
4In a separate bowl mix cornstarch and cold water. Stir into soup and simmer. If not to desired thickness add another mixture of cornstarch and cold water. Heat through, season with salt and pepper, and serve.