OK, here's a reply from the UK!

Remember oxo's got carbs in it so you need to allow 2 g for each oxo cube!

Try this.
Dissolve your cube in hot water as usual. Place in a pan on the gas. Break an egg and slowly dribble the contents in while you stir. Keep stirring until it's just about to boil. It should now seem thick. If it lookes curdled, just put it in a food processor (blender) and liquidise it. Voila, cheap thick gravy!