French Onion Soup Grilled Cheese

The Spruce
  • 50 mins
  • Prep: 5 mins,
  • Cook: 45 mins
  • Yield: Serves 2
Ratings (18)

Take all the classic flavors of French Onion Soup and turn them into one majorly decadent sandwich. With caramelized onions and plenty of gooey gruyere, this sandwich might give both the soup and normal grilled cheese a run for its money.

What You'll Need

  • 1 large yellow onion, sliced super thinly
  • 2 tablespoons butter
  • 2 tablespoons olive oil
  • 2 tablespoons red wine
  • 4 pieces good bread, you can use any you like
  • 2 tablespoons mayo
  • ½ lb gruyere cheese, sliced thinly

How to Make It

1. First caramelize the onions. Heat a skillet over medium heat. Add 1 tablespoon butter and melt. Add the onions and cook, stirring the onions continuously. This may take about 30 minutes. You want a uniform deep golden brown color. It’s worth the wait!

2. When your onions caramelized, add the red wine to deglaze the pan. Scrape up any brown bits and let the wine evaporate at least half. Season with salt and set aside.

3. Slather each slice of bread with some mayo. The mayo side is the outside.

4. Take 1 slice of the bread and on the un-mayoed side, put a big spoonful of onions. Top with half the cheese and close with the other slice of bread. Again, mayo side out. Do this twice for the 2 sandwiches.

5.  Place the remaining butter in a skillet and heat over medium high heat. Grill both sides until golden brown and cheese is melty.