French Onion Soup

1: Heat a large pan to medium-low heat.

2: Add butter and oil, then add the sliced onions.

3: Mix every 5 minutes for 30-40 minutes until the onions are golden brown.

4: Add salt, pepper, and flour to the onions and sauté for 3 minutes.

5: Remove the mixture to a large stock pot.

6: Add beef stock and scrape the bottom of the pan to deglaze.

7: Add the bay leaf, thyme, Worcestershire sauce, apple cider vinegar, and stir.

8: Let simmer for 10 minutes.

9: Ladle into bowls and top with croutons, a slice of provolone, and a slice of Swiss cheese.

10: Broil for 3-5 minutes until nice and bubbly. Be careful not to burn your tongue.