Name: Instant Pot French Onion Soup
Prep time: 20 min
Cook time: 20 min
Total time: 40 min
Ingredients: 2 tbsp butter; 10 medium-sized yellow onions, sliced; 1/2 tsp each salt & pepper; 1/2 tsp dried thyme; 2 tbsp flour; 1/2 cup red wine; 6 cups beef broth; 6 slices baguette, sliced about 1/2 inch thick; 3/4 cup Gruyere (Swiss) cheese

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This Instant Pot French Onion Soup is a restaurant-quality dish with caramelized onions, red wine & beef broth, finished with baguette slices & Gruyere cheese.

French onion soup ingredients

This French onion soup recipe is super easy and basic, but FULL of flavour! Here’s what you need on hand – full ingredient amounts are listed in the recipe box below.

Butter
Yellow onions
Dried thyme
All-purpose flour
Red wine – Use a dry red wine that you enjoy drinking
Beef broth – If you prefer beef stock or bone broth, they’re both great options
French baguette, cut into 1/2 inch thick slices
Gruyere cheese – This nutty cheese tastes similar to Swiss or Emmental, but with less holes and a harder rind

What makes French onion soup French?

This delicious onion soup has roots in France. It originated in the 18th century, as a dish for King Louis XV.

How to make French onion soup in the Instant Pot

This classic soup is SO easy to make thanks to your Instant Pot, and it comes together in half the time. Here’s how to make it:

Thinly slice your onions while your Instant Pot heats up. (Set it to saute mode).
When the pot is hot, melt the butter and then add the onions. Saute them for 15 minutes or so, until they start to brown. To prevent them from sticking to the bottom of the pot, stir them occasionally and scrape any brown bits off the bottom.
Add salt, pepper, thyme and flour, stirring until the onions have a nice coating of flour.
Pour in your red wine, then saute for a couple of minutes to reduce the wine a bit. From there, you’ll add the beef broth, then place the lid on your Instant Pot and pressure cook for 5 minutes.
Meanwhile, slice your baguette, grate the cheese and set your oven broiler to high so that you’re ready to melt the cheese once the soup is ready.
When soup is ready, ladle into ramekins or oven safe bowls, then top with a slice of baguette and sprinkle some cheese over the top. Broil for 2-3 minutes, watching closely, then serve and enjoy!

Caramelizing the onions

Caramelized onions have amazing flavour, but that wonderful taste requires time and patience. Within 15 minutes or so you’ll have browned onions and they will have shrunk down by half – you’ll also know they’re caramelized when they start to release a nutty, sweet aroma. The process isn’t quick, but the taste is something that you will never forget, and it’s a worthwhile first step in this Instant Pot version of French onion soup.

Leaving out the wine

If you need or want an alcohol-free version of the soup, you can absolutely omit the wine, or use cooking sherry. There isn’t much wine in the soup anyway. To be honest, the majority of the flavour comes from the caramelized onions anyway!

Making French onion soup keto

While onions are not the best choice for a keto diet, you can enjoy this soup as a rare treat. There are a lot of natural sugars in white, yellow, and red onions.

A half cup (58 grams) of sliced raw onions contains 6 grams of carbs, 1 of which is fiber.

However, you will definitely need to omit the croutons from the recipe. Of course, you can add as much cheese as you please on the top!

What can I use instead of Gruyere cheese?

Gruyere is a nutty cheese that tastes similar to Swiss cheese. Depending on where you live, it can be pricey though.

Feel free to use traditional Swiss, Emmental, baby Swiss, or even Provolone or mozzarella.

Other ingredient substitutions & notes

Onions – Yellow onions caramelize the best, but you can use white if that’s all you have on hand.
Red wine – The key is to use a wine you enjoy drinking. Any dry red or white wine will work perfectly. Or, you can omit the wine completely.
Beef broth – If you want to make a vegetarian French onion soup, feel free to use vegetable stock.
Cheese – Feel free to use any type of cheese that melts well and has a mild flavour. Mozzarella and Swiss cheeses are great substitutes for Gruyere

Storing and reheating

If you want to store any leftovers, be sure that you do so before adding the baguette and cheese to it. Keep the soup in an airtight container in the fridge for up to a week.

Reheat your soup in a pot on the stove top. Or, use your Instant Pot’s saute function to reheat the soup in your Instant Pot.

Then, ladle it into oven-safe bowls, place the baguette and shredded cheese over the top, and place it under the broiler to melt the cheese.

Freezing onion soup

You can freeze the soup without the baguette and cheese. It should keep well frozen for about 2-3 months. You can freeze in individual servings in glass bowls and then reheat from frozen for 6-8 minutes in the microwave, stirring halfway through. Add your baguette and cheese fresh and you’ll never know the soup was once frozen!

More Instant Pot soup recipes

Meal prep tools for this recipe

Grab some glass meal prep bowls if you plan on turning this onion soup into leftovers
Freeze this recipe in glass microwave-safe bowlsup to 3 months