Classic French Onion Soup

This recipe is from the America's Test Kitchen Cookbook (which is so often my go-to guide for a good recipe), though instead of using red onion as they suggest, I used sweet white onions.  The key to great flavor in this soup is the time spent cooking the onions--don't rush it!  I like to serve French Onion soup with slices of baguette that have been broiled with provolone or swiss cheese on top.  To do this, all you need to do is broil (500 degrees) the bread slices and cheese for 1 to 2 minutes (watch it carefully!) in the oven on a cookie sheet.

Ingredients:

• 3 large onions, peeled and thinly sliced in half-rings (you should end up with 4 to 5 cups of onion)
• 2 tbsp butter
• salt
• 1/2 tsp dried thyme (or 2 tsp fresh)
• 2 whole bay leaves
• 1/4 cup balsamic vinegar
• 2.5 cups chicken broth (preferably reduced sodium)
• 2 cups beef broth (also reduced sodium)

After the onions are sliced, heat the butter in a large dutch oven over medium heat.  Add the onions, 1/2 tsp salt and the thyme; stir to coat the onions in the butter.  Occasionally stir the onions, but allow them to cook until very soft and golden brown (about 30 minutes).  When they have some caramelized coloring, add the balsamic vinegar and scrape any brown bits off of the bottom of the pan.  Next, add the broth and the bay leaves.  Bring to a simmer, and allow to cook 15 to 20 more minutes.  After simmering, remove the bay leaves from the soup.  

Right before the soup is done simmering, broil your bread slices so they'll be hot when the soup is done.  If you've got a thing for croutons, go that route instead!  Either way, you'll have something to sop up that delicious broth.  Enjoy!