From Cooking Light 11/08....."Caramelizing enhances the onion's inherent sweetness. If you can't find sweet onions, substitute two large Spanish onions and add a tablespoon of sugar. This dip is best served warm. If time is tight, you can caramelize the onions (step 2) earlier in the day; combine with the other ingredients and bake just before guests arrive. Serve with a crunchy dipper like melba toast."