Preheat: Preheat the oven to 300°F (149°C) and spray a 9x13 inch baking dish with non-stick cooking spray.
Season the beef: Arrange the beef cubes in a single layer in the baking dish and season with salt and pepper to taste.
Combine ingredients: In a separate bowl, mix together the Beefy Onion Soup Mix, cream of mushroom soup, brown gravy mix, and water until well combined. Pour the mixture over the beef, stirring to coat evenly.
Bake: Cover the pan tightly with foil and bake on the middle rack of the oven for 2 1/2 to 3 hours without opening the oven.
Cool and serve: When ready, remove the pan from the oven and let it cool for a few minutes. Carefully remove the foil to avoid steam burns, as the dish will be hot.