Heat the stock in a large saucepan, add
the onions, sugar, salt and pepper. Cook over a low heat, covered, for
35 minutes, until the onions color slightly.
Add the vinegar and cook for 30 minutes,
covered, over a low heat; the onions should be very soft. Adjust the
seasoning and serve
Serves 8
The long, slow cooking intensifies the
natural sweetness of the onions.