Roasted Vidalia Onions with Balsamic Glaze

When we lived in Atlanta, the huge bags of Vidalia onions would be available in the spring.
These are sweet onions and I found this recipe - using a cast-iron pan makes the onions brown evenly and gives them a rich taste. 

Ingredients 

4 medium sized sweet onions 

     (cut in half horizontally and peeled) 

3 TBS olive oil 

Salt 

White pepper 

1 to 2 tbs water

½ cup balsamic vinegar

2 tbs light brown sugar 

2 tbs butter

Directions 

Preheat the oven to 375F 

Rub the onion halves with olive oil. You can leave the outer skin on.  Sprinkle with salt and pepper.  Place the onions, cut side down in a large oven proof skillet in an oven over 375F. Bake uncovered until the onions are soft, about an hour. 

Scoop the onions up using a spatula and put them on a serving dish flat side facing up. 

Stir together the water, vinegar, brown sugar and butter in the skillet that the onions were roasted in. 

Scrape the skillet to dissolve the baked-on onion juices.  Heat to a boil.  Boil for several minutes to reduce, then spoon some over each onion.  Taste and add more salt if necessary.  Serve hot or at room temperature. 

You can use a balsamic glaze - use 1/2 the amounts shown, and just mix the glaze, butter and sugar in a dish and microwave it about 25 seconds to melt the butter. Omit the water. Spoon the glaze over the onions once plated. 

You can also reduce or omit the sugar. If you're using a flavored balsamic, like fig or cherry, then I would recommend reducing the sugar.