In a pan or pot whisk the beef stock, bouillon, Worcestershire sauce, browning and seasoning sauce, onion powder, and garlic powder together.
Place it onto a medium heat and bring it to the boil.
In the meantime mix the cornstarch and water in a small bowl or jug.
Pour it into the pan with the beef stock and keep whisking while you bring it to the boil and then let it simmer until it thickens. This will take about 8 – 10 minutes. Don’t stop whisking otherwise, it will get lumpy.