The Absolute Best French Onion Soup Recipe
Updated: Feb 2
French onion soup, a quintessential classic. Over the years, traveling all over the globe, I've had the chance to try many different adaptations of a basic onion and broth soup that has been passed off as "French Onion Soup".
Let's face it, there is a lot of onion soup recipes out there that are just really, really bad. Most "quick" style recipes end up tasting like muddy onion scented dishwater.
Here's the secret to the absolute best French onion soup recipe... ready? It's not the broth, or the herbs, the wine, or the type of butter you use..
It's the TIME it takes to extract the flavors from the onions.
How to Make The Best French Onion Soup
Ingredients You Will Need:
- 4 Large Yellow Onions
- 2 Large Sweet Maui Onions (Vidalia's will also work beautifully)
- 3 Tablespoons Unsalted Butter
- Kosher Salt & Fresh Ground Black Pepper
- 1/2 Cup of Water
- 4 Cups Low Sodium Chicken Stock (homemade is always best)
- 2 Cups Beef Stock
- 1/2 Cup Dry Sherry (do not use cream sherry!)
- 1 Tablespoon Balsamic Vinegar
- 1 Large Bay Leaf
- Baguette (Day old is always best)
- 8 ounces of Shredded Gruyere Cheese (also try smoked for an extra punch)
- 8 Sprigs of Fresh Thyme (combine with bay leaf, tied with butchers string in a bouquet garni)
Equipment You Will Need:
- Large Oven Safe Dutch Oven w/ Oven Safe Lid
Let's Get Cooking The Best French Onion Soup Recipe!
Preheat your oven to 400 degrees F. Adjust rack height to accommodate the dutch oven being in the center of the oven with the lid on. This is normally the lower/middle rack position.
Prepare the dutch oven by generously spraying the interior with non stick pan spray. Peel and slice all of the onions into 1/4 inch thick half-moons. Add the butter to the dutch oven. Next, place the onions into the pot, and sprinkle over 1 heaping teaspoon of the kosher salt on the top of the onions. Cover with the lid, and place the dutch oven into your oven for 1 hour. No peeking during this time!
After one hour, stir the onions, and adjust the lid slightly askew to allow for evaporation to take place. Return the pot to your oven and cook again for an additional 90 minutes, stirring the onions, and scraping the sides and the bottom of the dutch oven every 45 minutes with a flat wooden spatula.
After the 90 minutes of additional cooking time has completed, remove the dutch oven and place it onto your stove. Continue cooking the onions uncovered over medium to medium-high heat for approximately 15-20 more minutes to develop a rich and powerfully flavorful fond. It's important to stir frequently and to scrape the bottom and sides of the pot regularly. You will notice that the liquid will evaporate and browning or fond will develop. We want this fond to be a rich dark brown... not black! Stirring is key to prevent burning. If the onions begin to darken too fast, lower your heat to medium or medium-low. This is not the time to rush this process and burn the onions! After 15-20 minutes, you should have a nice dark fond on the bottom and sides of the pot. Move the onions to one side of the pot, and deglaze with 1/4 cup of water. Scraping vigilantly to get as much of that fond up as you can. Continue cooking for another 5-8 minutes, allowing another layer of fond to form. Repeat the deglazing process again twice more, for a total of three deglazes, with another 1/4 cup of water for the second deglaze, and for the final deglaze, add in the dry sherry wine and balsamic vinegar and stir frequently for 5 minutes until the vast majority of the sherry wine and balsamic vinegar have evaporated.
The onions will continue to get very dark brown as the fond layers are extracted by the deglazing process.
Upon completion of the final deglaze, add in the chicken and beef stocks, the bouquet garni, 1/2 teaspoon of kosher salt, 1/2 teaspoon of freshly ground black pepper. Next, scrape down the sides and the bottom of the pot one more time to get any remaining fond incorporated into the soup. Raise the heat to high, and bring the soup to a medium bubble simmer. Lower the heat back down to low, cover, and gently simmer for an additional 20 minutes.
While the soup is in its final simmer, slice the baguette on a hard bias into 1/4 inch thick slices, place it on a sheet tray in a single layer. Bake the baguette slices at 400 degrees until toasty and slightly golden brown, this normally takes about 7-11 minutes. Upon removing the croutons from the oven, adjust the oven rack to the upper-middle position, and set the oven temperature to broil.
Fish the bouquet garni out of the soup and discard it. It's done its delicious flavor job. Fill each oven-safe ramekin or soup terrine 3/4ths full of soup, and float a single layer of baguette croutons on top of the soup. Add a nice layer of the shredded Gruyere cheese, make sure to keep the cheese off the top of the serving vessel to prevent premature burning of the cheese. Broil for 3-5 minutes until the cheese is all melty and golden brown. Do not walk away from the broiler at this time!
Remove the serving vessels from the oven and let cool a full 5 minutes before serving to prevent taste bud scalding. While the soup is cooling, pour yourself a nice glass of wine. You've earned it!
Dig in and enjoy your French onion soup with gruyere cheese in all of its bubbly glory!
From our kitchens to yours, cheers and happy cooking!
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About the Author: Certified Master Chef, Sommelier & Wine Educator, Sean Andrade is the executive chef/owner of AWG Private Chefs, named the #1 Private Chef Company in California. Chef Sean has worked in the restaurant and hospitality industries worldwide for more than 25 years. His company AWG Private Chefs offers highly custom-tailored, bespoke private chef dining experiences, and private event catering in over 30 countries around the globe.