This vegan French onion soup is a savory classic. Made with caramelized onions, and rich broth, topped with homemade croutons and vegan cheese for a comforting and delicious appetizer or main course.

Vegan French Onion Soup served with homemade croutons and vegan cheese in a white bowl.

There’s something truly special about a warm bowl of soup, especially when it’s as comforting and delicious as our vegan French onion soup.

This vegan French onion soup is an easy 1-pot soup that requires minimal ingredients and effort. And what better way to top off your soup, than with some bread and cheese? We truly enjoy all soups with a piece of crusty bread, but adding homemade croutons and vegan cheese was a game changer!

This is a vegan soup recipe that keeps well in the fridge and, as the flavors develop more in the fridge, it tastes even better the next day! It will surely have you coming back for seconds!

Serve this soup as a hearty appetizer or main course at your next family gathering.

And if you love comforting, filling and delicious vegan soups, you will love our vegan broccoli cheese soup, vegan butternut squash soup and vegan chicken noodle soup.

Ingredients You’ll Need:

Ingredients Notes

Onions – You can use Yellow, White or Brown onions in this recipe. We found that cutting the onions vertically with the grain is the best way to enjoy them in this soup. We included how to slice your onions in the instructions below.
All purpose flour – We used all purpose flour to thicken up the soup slightly. If you prefer a more brothy type soup you can omit this ingredient.
Dry white wine – This contributes to a rich sauce and the alcohol cooks off completely. However, if you prefer not to use alcohol in cooking you can switch it for extra stock.
Fresh thyme – If you don’t have fresh thyme on hand you can replace it with dried thyme.
Vegan cheese – We used vegan mozzarella and it added just enough creaminess to the soup. However you can use any vegan cheese you prefer.
The vegan croutons – We found this soup much more enjoyable with vegan croutons. We’ve included instructions in the recipe on how to make your own homemade vegan croutons.

A close up photo of Vegan french onion soup served in a white bowl with croutons and vegan cheese

How to make Vegan French Onion Soup

You will find full instructions and measurements in the recipe card at the bottom of the post. This is a summary of the process to go along with the process photos.

With a sharp knife, chop off the top and bottom parts of the onion and then peel the outer skin.
Now place the onion on one of the flat sides and chop it in half .
Place one half on the side that you just cut and slice it in thin strips from top to bottom.
Repeat this process with the rest of the onions.

Preparing the onions for vegan french onion soup

In a large heavy-bottomed pot, melt the butter over low heat. Add the onions and sauté for about 60 minutes until caramelized (but not burnt), initially stirring every 3-5 minutes, then about once a minute near the end (around 50 minutes) of caramelization to prevent burning. Resist the urge to turn up the heat. You will burn the onions.

Melt the butter in a heavy bottomed pot and add the onions. Caramelize until golden in color.

After the onions have caramelized, add the garlic and sauté for 2 minutes until fragrant.
Add the flour and mix it in. Cook for an additional 1 minute.

Add the garlic and sauté for 2 minutes. Then add the flour and stir in.

Stir in the wine to deglaze the pan, using a wooden spoon to scrape up any browned bits on the bottom of the pan.
Add the stock, soy sauce, bay leaf, and thyme and stir to combine. Turn the heat up to medium until the soup reaches a simmer. Then reduce the heat to medium-low, cover, and simmer for at least 10 minutes. After 10 minutes, turn off the heat and discard the bay leaf and sprigs of thyme. Taste the soup and season with salt and pepper as needed.

Stir in the wine and deglaze the pan. Add the rest of the ingredients, taste and simmer until cooked.

Check on the soup. When the 10 minutes are up, remove from the heat.

While the soup is simmering you can make your croutons:
Preheat the oven to 400°F(200°C) and line a baking sheet with parchment paper. Set aside. (You can also bake the croutons in the air fryer at 400°F(200°C) for 2 minutes in batches.)
Slice the baguette into 1-inch thick rounds and then divide the rounds into quarters.

Slice the baguette into croutons size pieces

Add the croutons to a mixing bowl and drizzle over the olive oil and toss until coated.
Arrange them in a single layer on the prepared baking sheet.

Pour oilve oil over the croutons and mix. Place onto baking sheet.

Bake for 6-8 minutes, until the croutons are toasted and golden around the edges. Set aside.

Now you are ready for the final step of making your vegan French onion soup.
Switch your oven to the broiler. Once the soup is ready to serve, place your oven-safe bowls on a thick baking sheet. Ladle the soup into each bowl, then top with the croutons and your desired amount of cheese (I used about ¼ cup shredded vegan cheese for each).
Place the baking sheet on an oven rack with the tops of the bowls about 6 inches from the heating element and broil for 2 minutes, or until the vegan cheese is melted and bubbly (Keep a close eye on them so that they do not burn).

Assembly of the vegan french onion soup into ramekins

Remove from the oven and serve immediately while the soup is hot and bubbly. Top with fresh thyme, crushed black pepper and some extra croutons on the side.

How to caramelize the onions for the Vegan French Onion Soup

Here are a few tips on caramelizing onions:

Slicing the onions – Slice the onions thinly. If you slice them to big, it will take a lot longer to caramelize.
Use a large, heavy-bottomed pot – When a large amount of onions are too close to one another, they’ll start to steam and develop moisture which impedes caramelization.
Do it low and slow – Cook the onions on a low heat. Keep on stirring especially near the end to prevent burning and sticking to the pot. Resist the urge to turn up the heat. You will burn the onions.

Storing and Freezing

Storing – This vegan French onion soup keeps well in the fridge in an airtight container for up to 4 days. It gets better over time as the flavors develop!
Freezing – Freeze the soup in an airtight container for up to 3 months.

More Vegan Soups

The best vegan french onion soup served in a white bowl