How to turn French Onion Soup into a Sandwich: Challah + Onions + Smoked Gouda

Last week, my friend at work, Danielle, brought me yet another bag of onions.

The first time Danielle brought me a bag of onions, I made Onion Jam. The next time I made Pickled Onions.

This time I thought maybe I should make French Onion Soup.  I've had French Onion Soups a few times and have always liked the soft onions, the beefy broth and the warmth and comfort of the soup.

My favorite part, however, has always been the cheesy bread on top.

And then the light bulb went off in my head: why not turn the soup into a sandwich? Maybe I've been watching too many episodes of the Sandwich King? :)

Luckily, I had all the ingredients I needed: the onions, leftover Challah that my friend Stacey brought to our Rosh Hashanah celebration (home-made!!) and smoked Gouda cheese.

If you love bread and cheese, you are going to love this sandwich!

French Onion Soup Sandwich or Challah with Caramelized Onions & Smoked Gouda
Ingredients (for 4 sandwiches)
1 tablespoon olive oil
2 large onions, thinly sliced {do this by hand: I've found that food processor doesn't really work for this}
salt & pepper
4 slices of Challah {or use any good white bread or even sourdough}
4 slices smoked Gouda

Directions
1. Heat a heavy bottomed pan {I use my beloved Le Creuset: seriously, I've been getting SO much use out of it since my parents sent it to me in March for my birthday: it's a round 5.5 Quart in Turquoise color}
2. Add the oil and heat. Add the onions and cook for about 20 minutes, stirring occasionally.
3. Add salt and pepper and cook for another 5 minutes. If you have a lot of patience, you can probably cook the onions longer, but I was happy with the results I achieved after 25 minutes.
4. Slightly toast challah slices.
5. Divide the caramelized onions among the challah slices, top with smoked Gouda and broil until the cheese has melted and starts to bubble. {Be incredibly careful not to burn the cheese or challah}

This would be so good with a bowl of tomato soup, don't you think?
Have you ever made a sandwich that reminded you of your favorite soup?