You can cut one of those gigantic onions in the supermarket into four big cookies. Brush a bit of oil(olive oil is OK if you do not use Extra Virgin) onto a cast iron pan, heavy bottomed frying pan or griddle. On meduim to low heat, fry the onions, turning rarely and occasionally spritzing them with a little water. Keep the disks together. Cover them through much of the middle cooking time. In the restaurant, we just turn a paper serving boat upside down over them. You do not need much. Keep turning and spritzing till the onions are still slightly firm in the very middle only, and the flat sides have taken on a very dark rich color.
Remove them to a pan or serving bowl. Sprinkle with a bit of salt, pepper and Extra Virgin Olive Oil. The onions will continue to cook after removing them from the heat, but there will still be plenty of texture left and should retain the shape of the disks. A sprinkling of wine vinegar, lemon juice or balsamic vinegar will cut a bit of the sweetness of the onions...and they will be very VERY sweet. Serve them with chunks of bread, cheese, fruit and olives or Caper Berries.