I made one after someone at our class mentioned the recipe, or what I can remember of it!!
1 White Onion,
1 Red Onion,
Beef Stock
Chop the onions and fry in frylight and then add the beef stock with water and leave to simmer. Strain, Season to taste.
Now personally I found it a bit sweet so I think perhaps I missed something out so i shall stalk this thread to see what others say!