This Instant Pot French onion soup is the ultimate in deliciousness - and the pressure cooker is the easiest way to make it. Rich beef broth, sweet caramelized onions, fresh herbs, and gooey melted cheese come together making the most amazing classic French recipe ever! Everyone can enjoy this cozy comfort food with the lower carb, gluten free, and keto option too!

The Best French Onion Soup!
Okay, I know this is my recipe but I LOVE it. It turned out so delicious it has become one of my favorite recipes of all time.
Best Flavor
This French onion soup Instant Pot recipe is a keeper! Cooking in a pressure cooker, with only one pot, is wonderful. I think that pressure cooking mellowed the caramelized onions and blended the flavors even more so that if I had done them in a pot on the stove. Yum.
Comfort Food
This is the perfect cozy comfort food recipe when it gets chilly! French onion soup is like a warm hug on a cold night. Okay, maybe a warm sweater? 🙂
Make Ahead.
You can easily make this French onion soup recipe ahead of time. It also reheats really well! I froze individual portions in the freezer, and when thawed, it tastes as good as if you just made it.
What You'll Need To Make Instant Pot French Onion Soup
- Sweet onions: (I used half red onion and half white)
- Extra Virgin Olive Oil
- Butter
- Garlic
- Beef broth or beef bone broth
- White wine
- Beef bouillon base
- Thyme
- Kosher salt
- Ground black pepper
- Cornstarch or xanthan gum: optional thickeners, xanthan gum is the gluten free and low carb option.
- Gruyere cheese: Swiss is fine too, but I prefer Gruyere for its buttery, nutty taste.
- French bread: for croutons if you're not following a low carb or keto plan.
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How To Make French Onion Soup in Instant Pot
Croutons
- Start by making the croutons and while they are baking, move on to the soup.
- Preheat oven to 425°
- Brush french bread slices with oil and lightly sprinkle with salt on both sides. Place on a baking sheet and bake until crisp and golden brown. This takes between 15 and 20 minutes. Flip halfway through baking. Remove from the oven and set aside.
Soup
- Set the pressure cooker to Sauté Medium. Melt butter and olive oil in the bottom of the cooker. Add onions and sauté, stirring occasionally, until they are very soft and golden in color. Do not rush this process, you want the onions super soft and caramelized.
- If your pot gets too hot, turn it down to Low and continue on.
- Add broth, bouillon base, wine, and thyme.
- Secure lid on the pressure cooker. Set to pressure High for 2 minutes. Once complete, allow pressure to be released manually. Tip: if you get distracted and need to let it release manually, this is totally fine too!
- Dissolve a half teaspoon of xanthan gum with an equal part of olive oil and mix into the soup as a low-carb thickener. Mix cornstarch slurry of 1:2 ratio - use 1 tablespoon of cornstarch and whisk together with 2 tablespoons of cold water. Add to the soup and stir. Turn the pot to saute low and stir frequently until it starts to thicken.
- Season with salt and pepper.
Top with Crouton and Broil
- Low carb and keto followers dish the soup, skip the crouton, and move on to serving.
- Dish soup into oven-safe bowls and top with a crouton.
- Top the crouton with a fourth of a cup of Gruyere cheese.
- Turn oven on broil. Place soup bowls in the oven and broil until cheese is melted and bubbly.
Serve
- Sprinkle with Gruyere cheese, garnish with fresh thyme, and serve.
FAQ's
1 medium onion has approximately 10 g of carbohydrates and 1.9 g of dietary fiber, so 8.1 net carbs. The majority of the carbs in this French onion soup recipe are from the onions.
There are 338 calories in french onion soup with NO crouton, There are 511 calories with the crouton.
Yes. French onion soup has alcohol. Usually, this is a dry white wine, vermouth, or cooking wine.
Yes. You can substitute beef broth instead of wine.
French onion soup should taste like a deep rich beef broth, with a mellow caramelized onion and herb taste. Gruyere cheese adds another buttery rich layer. The crouton absorbs the broth and slightly thickens the soup.
A beef roast or steak pairs nicely with a french onion soup. A salad makes a nice side dish.
You can use Swiss cheese instead of gruyere cheese. Swiss is the closest equivalent and easy to find in the U.S. It is also less expensive than gruyere cheese which is imported from France.
Yes. You can freeze french onion soup. I like to freeze in individual microwave and freezer safe containers so I can take to have for lunches or take to work at a later time.
Can I ask you a favor?
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📖 Recipe
Instant Pot French Onion Soup
Ingredients
Soup
- 3 cups thinly sliced red onions (2 to 3 small to medium)
- 3 cups thinly sliced sweet yellow onions (2 to 3 small to medium)
- 2 tablespoons olive oil
- 4 tablespoons butter
- 2 garlic cloves (minced)
- ½ cup dry white wine (port, sauvignon blanc, white cooking wine, or vermouth also work)
- 32 ounces beef broth (bone broth is really good here)
- 1 tablespoon white wine vinegar
- 1 teaspoon beef bouillon base
- 3 teaspoons fresh thyme (tarragon is also nice)
- ¼ to ½ teaspoon each kosher salt and pepper to taste
- 2 cups gruyere cheese grated (swiss is fine too)
- optional thickeners: ½ teaspoon of xanthan gum (low carb) dissolved in ½ teaspoon olive oil, or 1 tablespoon cornstarch whisked with 2 tablespoons of cold water.
Croutons
- 6 slices french bread ½" thick (not for low carb or keto followers)
- 4 tablespoons olive oil
- salt
Instructions
- Preheat oven to 425°. Brush french bread slices with oil and lightly sprinkle with salt on both sides. Place on a baking sheet and bake until crisp and golden brown, about 10 and 20 minutes. Flip halfway through baking. Remove from oven and set aside. (Tip: croutons can be made in advance)
- Set the pressure cooker to Sauté Medium. Melt butter and olive oil in the bottom of the cooker. Add onions and sauté stirring occasionally until they are very soft and a golden color, about 15 to 20 minutes (or as needed). Do not rush this process - you want the onions super soft and caramelized. (Be careful not to burn the onions - if your pot gets too hot, turn it down to Low and continue on.)
- Add broth, bouillon base, wine, thyme, salt, and pepper.
- Secure the lid on the pressure cooker. Set the pressure to High for 2 minutes. Once complete, allow the pressure to release manually.
- Dissolve the thickener in water or olive oil. Slowly whisk the thickener into the soup and stir until it starts to thicken. Adjust salt and pepper levels if needed.
- Dish soup into oven-safe bowls and top with a crouton. Top the crouton with ¼ cup Gruyere cheese. Place bowls on a baking sheet.
- Turn the oven to broil. Place the soup bowls in the oven and broil until the cheese is melted and bubbly on top.
- Remove from oven and garnish with fresh thyme.
Kori's Tips
- Don't miss all of our helpful hints, substitution ideas, cooking tips, and other delicious recipes that can be found in our post. Check it out!
- LOW CARB, GLUTEN FREE, and KETO VARIATION: Omit the crouton or use a keto, gluten free bread that works for your plan. Use the optional xanthan gum thickener to thicken the soup slightly if needed.
- SERVING SUGGESTIONS: Serve with a fresh green salad and a favorite salad dressing.
Nutrition
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