For this recipe, I made my soup in a large heavy bottom skillet with high sides, as it works best for caramelizing the onions. I find that a larger surface area works best when carmelizing onions as the moisture and steam can more easily evaporate during the cooking process. If you’d like, you can absolutely use a soup pot, but keep in mind it may take longer to caramelize your onions. Either way, you’re going to have a super yummy French onion soup!

How to make French Onion Soup from Scratch

1. In a large heavy bottom skillet or pan, melt butter. Add the sliced onions, stir to combine with the butter, and allow to cook at medium high heat. Do not stir yet! Allow the onions to cook for at least 5-8 minutes before you stir – this will allow your onions to begin to caramelize. Repeat this until the onions have become brown and caramelized – stir only occasionally as too frequent of stirring will prevent the onions from caramelizing. The onions need to stay in contact with the surface of the pan for a while in order to brown up enough to pull the flavor out of the onions. I like to cook my onions for at least 40 minutes in order to brown up enough. You may need to adjust your temperature as the onions cook – higher or lower depending on how caramelized they’re getting. You’ll be ready for the next step once the onions are sticky and a rich brown color. 
2. Next add garlic, the bay leaf, salt and pepper. Take 3 of the sprigs of fresh thyme and pull the leaves off and drop them into the onion mixture. Give everything a stir to combine.
3. Turn down the heat. Sprinkle the all purpose flour into the onion mixture one tablespoon at a time, stirring in between. Ensure that you stir out any lumps. Cook and stir the mixture for about 3 minutes. The mixture should get more sticky.
4. Next add the dry white wine to the pan to deglaze – basically, in this step, the wine will pick up all the tasty bits that are on the bottom of the pan and help re-incorporate it into the onion mixture. When combining with the wine, be sure to use your spoon to scrape up any bits that are sticking to the bottom of the pan. Allow this mixture to cook for about 5-8 minutes.
5. Add the beef broth, combine and allow to simmer for about 30 minutes. You can allow it to simmer longer if you like – it’s up to you! I find the longer the soup simmers, the better the flavor, but please simmer no less than 30 minutes for the best results. 
6. Next, top with crusty French bread croutons, sprinkle with cheese and melt until bubbly according to one of the methods below. Sprinkle with additional fresh thyme and serve!

To make the Crusty French Bread Croutons for the soup

1. Take your sliced French bread and place them on a wire rack over a rimmed baking sheet. Place them in the oven to bake for 2 minutes at 250°F. When they’re ready, they should be firm and dry, like large croutons. Set aside until needed for topping your soup when serving. 

3 Methods for Melting the Cheese on your Croutons when serving French Onion Soup

There are several ways to give the cheese on your croutons a beautiful golden and melty texture! Choose whichever way works best for you – all work great!

Method 1: Ladle the soup into oven safe bowls, then place a prepared crouton on top, sprinkle liberally with gruyere cheese. Place each bowl onto a metal baking sheet, then place them into the oven. Turn on your broiler and watch very closely! Once the cheese is melted and bubbly, they’re ready! Be careful when serving because the bowls will be very hot – allow to rest for at least 5 minutes before serving. Sprinkle with additional fresh thyme and serve.

Method 2: After your sliced French bread has toasted in the oven, sprinkle the tops with cheese and return to the oven. Turn on the broiler setting for your oven and watch closely. Once the cheese is golden and bubbly, they’re ready. Place the croutons with cheese on top of each bowl of french onion soup, sprinkle with additional fresh thyme and serve!

Method 3: If you have a kitchen torch, try this! This is my favorite method as it gives the cheese a nice subtle char flavor. Place toasted croutons on top of each bowl of french onion soup, sprinkle with cheese, then torch the tops until the cheese is melty and bubbly with a slight char. Sprinkle with additional fresh thyme and serve!