This classic French Onion Soup features deeply caramelized onions in a rich beef broth, topped with toasted baguette slices and melted Swiss and mozzarella cheeses, broiled to golden perfection.
In a large pot over medium heat, melt the cold butter until frothy, add the finely sliced onions & garlic. Sauté until onions until caramelized, don’t rush this process! It may take up to 15 mins. Deglaze caramelized onions with white wine, followed by beef broth. Add bay leaves, oregano & thyme — let gently simmer over medium heat for 10 – 15 mins. Now add the balsamic vinegar, white wine vinegar & Worcestershire sauce. Stir to combine & taste. If salt is needed to balance, add 1 tsp at a time. If bolder flavor in the broth is desired at more Worcestershire sauce 1 tsp at a time. Ladle soup into oven safe bowl & lay baguette slices on top to float. Add slice of Swiss cheese on top of bread & top with grated mozzarella. Broil for 3-6 minutes until golden & bubbly. Let cool for a few minutes before enjoying as it will be very hot!
