French Onion Soup is by far the most requested soup for dinner parties with our friends and family. My vegetarian take on this rich and indulgent dish boasts flavors of caramelized onions, toasty buttered croutons, sweet thyme and of course, melted gooey cheese.
Traditional recipes can be time consuming; but with the help of the Instant Pot, this French onion soup will be ready in under an hour. It has the same luxurious flavors and sweetness from caramelized onions which are topped with toasty croutons and cheese and broiled to golden perfection. My all time favorite, Instant Pot Sauté option, perfectly cooks the onions followed by the pressure cooking option, that seals all the flavors inside. Infused with bay leaf and fresh thyme, this French onions soup is a must-try recipe.
Traditionally made with beef broth, I love making a vegetarian version of this classic french onion soup with the Better Than Bouillon seasoned vegetable base that adds concentrated flavors and perfect color to the soup. I like to use large yellow onions in this soup because they lend to a mellow, sweet taste with the perfect brightness in the end. The onions can be sautéd to a caramel color in about 20-25 minutes, stirring every 5 minutes or so.
Although dried thyme can be used in a pinch, to me, fresh thyme is a must-have for this classic soup. I add it while pressure cooking along with bay leaf and then garnish again with thyme for a pop color. The Worcestershire sauce adds a savory, umami flavors to the soup and is also available as a Vegan option.
A crusty baguette, sliced in to thick bite-sized pieces, makes homemade croutons in no time. Brush them with some butter for more rich flavors.
The key ingredient to a great tasting french onion soup is fresh, good quality cheese. A large handful of shredded Gruyere cheese and sliced Swiss cheese are broiled just until the cheese melts and starts to brown. I like to finish the soup with a sprinkle of spicy cayenne pepper that perfectly balances the flavors of this classic bistro soup.
Here is a quick video on how to make this crowd pleasing, winter comfort soup in the Instant Pot:
A rich and comforting, French Onion Soup with toasty bread croutons, melted Gruyere and Swiss cheese with sweet caramelized onions cooked in a flavorful broth.
- 4 large yellow onions thinly sliced (use mandolin for thin slices)
- 3 tablespoons butter
- 1 tablespoon cooking oil
- 1 teaspoon kosher salt
- ¼ teaspoon sugar
- 1/2 cup dry white wine
- 1 tablespoon Worcestershire sauce/ Vegan Worcestershire sauce
- 1 bay leaf
- 1 tablespoon fresh thyme
- 1/2 teaspoon crushed black pepper
- 3 cups veg broth low sodium
- 2 tablespoons all purpose flour
- 1 crusty baguette thick slices
- 1-1/2 cups shredded gruyere cheese
- 6-12 slices swiss cheese
- 1 teaspoon cayenne pepper optional
- Turn the Instant Pot on Sauté(more) mode and heat butter and oil.
Add onions, ½ tsp salt, ¼ tsp sugar and cook for 20-25 minutes stirring every 5 mins until onions turn golden brown but not burnt. Glass lid can be used during Saute process. After 20 minutes the onions should be golden brown and the bottom of the pot will start to brown.
- Press Cancel. Add wine and deglaze the pot removing all browning from the pot. Cook for 2-3 minutes as the wine evaporates.
- Add bay leaf, 1/2 tablespoon thyme, remaining salt, pepper, worcestershire sauce and 2-1/2 cups of broth. Secure the lid with Pressure Release to Sealing. Cook on Manual/Pressure Cook (Hi) for 6 minutes followed by Quick Release.
Open the Instant Pot, remove the bay leaf and discard. Mix all purpose flour in the remaining broth and slowly stir in the soup. Set Instant Pot to Sauté mode and cook for 5 minutes as the soup thickens.
- Preheat oven to broil(Hi). Cut each baguette slices into bite sized pieces. Line them on a baking sheet and toast until golden brown (5 to 7 minutes).
- Add 3/4 cup of soup to an oven safe bowl. Add toasted bread pieces and top them with handful go shredded Gruyere cheese, top with Swiss cheese slices and a sprinkle of cayenne pepper and thyme. Broil for 5 mins or until the cheese melts. Serve hot!
Recipe Video
Use a mix of red and yellow onions.
Dry thyme can be substituted for fresh.
Author: Archana
Hey there! I am a techie turned recipe developer, cooking instructor, and food blogger. I love food and enjoy developing easy and healthy recipes for busy lifestyles. I live in New Jersey with my husband and two sons.
woodboneandstone says
Thank you for this vegetarian version!
Archana says
You are welcome!
Laura @ Feast Wisely says
Love this recipe Archana – something my hubby has always wanted to make! I’ll be sharing your technique with him
Archana says
Thank you Laura! I can’t wait to hear how he likes it.
Blogtastic Food says
Looks so delicious!! Still yet to try French onion soup (:
Archana says
Give it a try! You will love the flavors of homemade French onion soup
Pamela S Gupta says
Made this today as an Easter lunch for myself. The diner versions have always been my guilty pleasure, but haven’t always left me feeling so great. This.is.DIVINE. Used homemade chicken stock & a ton of onions; poured it over some crusty bread & topped with freshly grated parmesan. Your proportions are spot on & the flavor is just delicious. Thanks!
Archana says
Hi Pamela! Happy Easter. Thank you for your lovely feedback. Happy to hear that you enjoyed the flavors. This is our family favorite recipe
Nathan says
This was a huge hit for our Easter! Thanks so much.
Archana says
Happy Easter! So glad you enjoyed this. It is out family fav.
KALBAP says
Hello Archana, this recipe made for a hearty lunch with the family. Everyone loved it. And fairly easily made.
Archana says
Thank you! I am so glad your family enjoyed it.
KALBAP says
Just make sure it appears in the “instapot soups tab”
Archana says
Good catch, Thank you! Updated.
Werra Watson says
Thank you for offering up the Vegetarian option. In the Article you mentioned using the Better the Bouillon seasoned vegetable base but I do not see it listed in your actual recipe. How much of this is used in the recipe?
Archana says
Hi Were, So the recipe calls for 3 cups of vegetable broth. To make that you add 3 teaspoons of better than bouillon base to 3 cups of water. Let me know if you have any other questions.
Ashley says
Is it okay to use dried thyme instead of fresh thyme? Thank you so much!
Archana says
Yes!
Judy says
Made this for the 3rd time last week. Delicious as usual! One question, I froze most of the extra but realized I left one container in the fridge, how long will it keep in the refrigerator? I hate to throw it away, it still smells great.
Archana says
I would say easily upto a week. Also if it smells good then it’s good to eat
Mary Anne says
Can I double this? I have a 8 quart duo plus.
Archana says
Yes you can double
Cheri A Magistro says
Hi! Looking to make this today. Have 2 questions, can I use something else rather than wine to deglaze? Also, is there a replacement for the flour? I try to stay as low carb as possible. Thank you.
Archana says
Sorry if I am replying this later. Water can be used instead of wine to deglaze.Its only 2 tablespoons of flour, but if you wish to skip it you can, the soup will not be as creamy.