This Instant Pot French Onion Soup is deeply satisfying and easy to make. Caramelized onions simmered in a rich broth, finished with toasted bread and melted cheese, create a comforting, restaurant-quality bowl in a fraction of the time when made in a pressure cooker.

Originally Published on 9/4/2018
French Onion Soup in the Instant Pot
The Instant Pot lets you brown the onions and pressure-cook the soup in the same pot, cutting down on time and dishes while still delivering that deep, caramelized-onion flavor. It’s a smart, convenient way to make this classic.
What is French Onion Soup?
- French Onion Soup is a traditional French dish made from slowly caramelized onions cooked in a savory beef-based broth, typically topped with a slice of toasted bread and melted, browned cheese.
- The dish is prized for its rich, sweet-savory onion flavor and the contrasting textures of crunchy toasted bread and gooey melted cheese.
Serve this to guests for an impressive, comforting starter or a hearty main that showcases simple ingredients handled well.
Which Onions Work Best?
Yellow or white onions are classic choices. Adding a couple of sweet onions helps the caramelization and adds a pleasant sweetness that balances the savory broth.
Best Cheese for Topping
Gruyère is the traditional and preferred choice for French Onion Soup because it melts well and browns beautifully. Swiss, provolone, or mozzarella are fine alternatives if needed.
Best Bread for the Topping
Thick slices of French bread or a baguette are ideal. Toast the slices before placing them on the soup so they remain slightly crisp under the melty cheese.

How to Make French Onion Soup in the Instant Pot
1) Prepare and measure your ingredients; thinly slice the onions and grate or slice the cheese.
2) Sauté the onions: Use the Instant Pot Sauté setting on Low or Normal and add butter (or olive oil) once the pot is hot. Cook the onions slowly until they brown and caramelize.
3) Deglaze: Add brandy (or red wine/sherry), Worcestershire sauce, and a bit of butter. Scrape up the browned bits from the bottom of the pot and simmer briefly to reduce.
4) Add broth: Pour in beef (or vegetable) broth and scrape the bottom again to release any remaining fond.
5) Pressure cook: Cancel Sauté, close the lid, set the valve to Sealing, and Pressure Cook on High for 5 minutes.
6) Natural release: Let the pot naturally release for 10–15 minutes, then carefully finish with a quick release and open the lid.
7) Prepare toppings: While the pressure releases, toast slices of French bread or baguette under the broiler.
8) Assemble: Ladle soup into ovenproof bowls, top each with a toasted bread slice, then cover generously with Gruyère or another melting cheese.
9) Broil: Place the bowls on a baking sheet and broil until the cheese is bubbly and golden, watching closely to avoid burning.
10) Serve: Remove carefully with oven mitts and let cool briefly before serving. The soup will be very hot.
Is Caramelizing the Onions Necessary?
- Caramelizing the onions isn’t strictly required, but it greatly enhances the soup’s flavor. The longer you caramelize, the deeper and sweeter the flavor becomes.
- If you’re short on time, cook the onions as long as you can; the soup will still be enjoyable but less rich in depth.
How to Avoid Mushy Onions
- Slice thinly: Thin, even slices cook and caramelize more reliably.
- Use moderate heat: Low to medium-low heat allows sugars to develop without turning the onions to mush.
- Stir occasionally: Prevent sticking and encourage even browning.
- Be patient: Proper caramelization can take 30–45 minutes when done on the stovetop; in the Instant Pot sauté mode it may take 10–25 minutes depending on settings.
- Avoid overcrowding: Cook in batches if necessary so the onions brown instead of steam.

Vegetarian Version
Yes. Substitute a good-quality vegetable broth for the beef broth. The flavor will be different but can still be rich and satisfying—consider using a mix of vegetable and mushroom broths for more depth.
Make-Ahead and Storage
- Prepare the soup base ahead of time and refrigerate. Reheat, then add toasted bread and cheese and broil right before serving.
- Refrigerate leftovers in an airtight container for 3–4 days.
- Freeze cooled soup in airtight containers or freezer bags for 2–3 months.
- Thaw in the refrigerator and reheat gently on the stove or in the microwave. Add bread and cheese only when ready to serve.

If you make this Instant Pot French Onion Soup, leave a comment and a star rating to share how it turned out for you.

Instant Pot French Onion Soup
Ingredients
- 1 1/2 Tablespoons Olive Oil
- 2 large Yellow Onions, thinly sliced
- 3 medium Sweet Onions, thinly sliced
- 1/8 teaspoon Baking Soda (optional)
- 3 sprigs Fresh Thyme
- 2 Bay Leaves
- 2 cloves Garlic, minced
- 1/2 teaspoon Kosher Salt
- 1/2 teaspoon Black Pepper
- 1/2 cup Brandy (or red wine or sherry)
- 1 1/2 teaspoons Worcestershire Sauce
- 3 Tablespoons Butter
- 4 cups Beef Broth (or a mix of broths)
To Finish
- 4–6 thick French bread slices, toasted (or baguette)
- 4–6 slices Gruyère cheese or grated (Swiss or provolone are alternatives)
Instructions
- Gather and prepare all ingredients. Slice the onions and grate or slice the cheese.
- Turn on Sauté (Normal or Low). When hot, add butter and olive oil.
- Add the onions and baking soda (if using). Stir to coat and cook, stirring occasionally, until onions are brown and caramelized (about 10–25 minutes in the Instant Pot sauté mode).
- Add thyme, bay leaves, garlic, salt, and pepper. Stir to combine.
- Add brandy and Worcestershire sauce, scraping up any browned bits. Cook a couple of minutes to reduce slightly.
- Stir in the beef broth and bring to a gentle simmer, scraping the bottom of the pot.
- Cancel Sauté, secure the lid, set the valve to Sealing, and Pressure Cook/Manual on High for 5 minutes.
- Allow a natural pressure release for 10–15 minutes, then carefully release any remaining pressure and open the lid.
- While the pressure releases, toast the bread slices.
- Remove thyme stems and bay leaves. Ladle soup into ovenproof bowls, set a toasted bread slice on top of each, and cover with Gruyère.
- Broil on a baking sheet until the cheese is melted and golden. Serve hot.
Notes
Baking Soda: A pinch of baking soda can speed caramelization by helping onions break down, but it’s optional—use sparingly.
If you skip long caramelization, the soup will still be tasty but less complex. For the broth, a mix of beef and chicken broth works well, or use all of one type.
Nutrition
Calories: 188 kcal (approximate)
Course and Cuisine
Course: Soup
Cuisine: French