Melted Red Onions with Balsamic Vinegar

Last week Scott made the most amazing French onion soup.  It started with some homemade stock and ended with me practically licking the bowl.  In the middle he made caramelized onions.  Not just any caramelized onions, but the most beautiful, slow-cooked, perfect caramelized onions I had ever seen.  When he showed me how they had cooked down to almost nothing, I knew that he had found the perfect cooking method for the balsamic onions I had been thinking about since our trip to Italy two weeks ago.

I came across the idea for the onions when I was reading Under the Tuscan Sun.  Rather cliché, I know, to read that book while I happened to be sitting under the Tuscan sun, or rather, under the Tuscan snow flurries, but it was on the bookshelf where we were staying, and I had just finished a book about the history of cleanliness and was looking for some more traditional vacation reading.  To be short, Frances Mayes mentions the onions and gives a recipe (I think).  Of course, I didn't write it down and had to leave the book behind, but the idea of the onions stuck with me.  Ultimately, this is a recipe inspired by the book, and more importantly, by Scott's cooking.  The onions are soft, flavorful, and perfect on toasted bread as an afternoon snack. 

Onions after 1 hour of cooking.

Onions after 2 hours of cooking.

Notes:
According to Cooks Illustrated, slicing the onions from pole-to-pole will help the onions retain their shape during the cooking process.  There is no need to stir the onions while they are cooking in the oven; just set your timer for an hour, and relax until it is time to attend to them.  The cooking method is adapted from Cook's Illustrated.

Ingredients:
6 pounds red onions
3 tablespoons butter
1 teaspoon salt
¾ cup + 3 tablespoons balsamic vinegar (divided use)
½ cup + 1 tablespoon olive oil (divided use)
Vegetable oil  or cooking spray

Yields 5 cups

Cut and Cook:
Adjust the oven rack to a lower-middle position, and preheat the oven to 400°F.  Cut the ends off an onion and then cut it in half from pole-to-pole (i.e., from the root end to the stem end).  Peel the onion halves, and cut them pole-to-pole into slices that are a ¼-inch thick.  Repeat with the remaining onions.  Lightly grease the inside of a large Dutch oven with vegetable oil and a paper towel or cooking spray.  Over low heat, melt the butter with the salt in the Dutch oven, and remove the pot from the heat once the butter is melted.  To the pot, add the sliced onions, a ¼ cup of balsamic vinegar, and a ½ cup of olive oil; toss gently to combine.  Cover the pot, place it in the oven, and cook for 1 hour. 

After 1 hour, carefully remove the pot from the oven.  Add an additional ½ cup of balsamic vinegar to the onions, and stir well, taking care to scrape the bottom and the sides of the pot to release any onions that may be sticking.  Partially cover the pot, and return it to the oven for an hour or until the onions are soft and reduced. 

Transfer the pot from the oven to the stove top and remove the cover.  Over medium-high heat, cook the onions, stirring frequently, for an additional 5 to10 minutes to evaporate any extra juices.  Additional time may be required, depending on the moisture content of the onions.  The end result should be onions that are moist, but not runny.  Remove the pot from the heat, and stir in a tablespoon of olive oil and 1-3 tablespoons of balsamic vinegar, to taste.  Once the onions have cooled slightly, transfer them to a container and store it in the refrigerator. 

Serve:
Eat warm or cold on a slice of toasted rustic or French bread. Pin It