Cooked Onion Salad

In the old days people used to put onions in their skins to cook very slowly in the ashes of a fire. They acquired a sweet, mellow taste which an hour in a low oven (160°C/325°F/Mark 3) will also give them. Put a few in while you are cooking something else. Let them cool, then peel and cut into slices or pieces and dress with a