Vegetarian French Onion Soup
on Dec 01, 2023, Updated Feb 26, 2024
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This vegetarian french onion soup is absolutely perfect! Deep flavors, butter, hours of caramelized onions, melted cheese and bread: my DREAM meal and hands down one of my favorite soups and tastes amazing.
A little different than the classic French Onion Soup with beef broth and not traditional by any means; this is made with a deep, homemade Vegetable Broth that is absolutely perfect. It’s also using white wine instead of red wine, as well as sharp cheddar instead of gruyere cheese and swiss cheese (although you can totally use that here as well).
What ingredients do you need for this vegetarian french onion soup recipe?
Onions: The star of this french onion soup! Caramelized with garlic, thyme and bay leaf, it is just the best, and your house will be smelling amazing. Balsamic adds depth of flavor to this soup, but you can also use soy sauce.
Homemade vegetable stock: If you don’t have time and don’t have the ingredients to make your homemade vegetable stock, that’s totally okay. Store bought is definitely fine here as well.
Cheese: Here I’m using white wine and sharp white cheddar, but you can totally use red wine or gruyere or swiss, like my classic french onion soup with beef stock. Both are just as delicious!
Bread: I prefer to toast my sourdough baguette and then add on the soup for finishing in the onion. This allows the bread to not get super soggy, just soft and crunchy at the same time. But if you’re in a pinch, just add your slices without toasting on the soup prior to the oven.
Flour: we add flour to the onions because it helps thicken up the soup, making it super creamy, giving it body.
Instructions to make this soup
Caramelize your onions
- Toss your onions with all-purpose flour.
- In a Dutch oven or deep soup pot, melt butter until glistened on medium heat, and add in your onions. Sweat out for about 15 minutes, tossing periodically, and then add in your garlic.
- Season with salt and pepper. Next, add your thyme, 1 bay leaf, balsamic vinegar, and white wine, and let reduce for 1 minute, until your wine has reduced.
- Caramelize your onions for about 1 hour on medium-low heat, adjusting with a splash of water, mixing, as needed to prevent burning and pick up any fond.
Add in your broth
- Once your onion mixture is cooked down, dark brown, and caramelized, add your vegetable broth and stir to combine. Warm and combine all the ingredients at a gentle simmer.
Prepare your bowls and broil!
- Preheat your oven to 400 degrees. Scoop your soup into oven-safe bowls, add a slice of bread (you can either pre-toast your bread and then add to let broil with the cheese, or place un-toasted in the broiler with the cheese) then a handful of shredded cheese.
- Broil or bake in the oven for 10 to 15 minutes until bubbly and melted. Top with fresh thyme and fresh cracked pepper.
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Vegetarian French Onion Soup
Ingredients
- 5 yellow onions, or mix of sweet and yellow, thinly sliced
- 2 tablespoons all-purpose flour
- 1/4 cup unsalted cold butter
- 2 large garlic cloves, minced
- Kosher salt and freshly ground black pepper
- 2 sprigs thyme
- 1 bay leaf
- 1 tablespoon balsamic vinegar
- ½ cup white wine
- 4 cups broth, we are using vegetable broth
- sourdough baguette slice and sharp cheddar to top each soup
Instructions
- Toss your onions with all-purpose flour.
- In a Dutch oven or deep soup pot, melt butter until glistened on medium heat, and add in your onions. Sweat out for about 15 minutes, tossing periodically, and then add in your garlic.
- Season with salt and pepper. Next, add your thyme, 1 bay leaf, balsamic vinegar, and white wine, and let reduce for 1 minute, until your wine has reduced.
- Caramelize your onions for about 1 hour on medium-low heat, adjusting with a splash of water, mixing, as needed to prevent burning and pick up any fond.
- Once your onion mixture is cooked down, dark brown, and caramelized, add your vegetable broth and stir to combine. Warm and combine all the ingredients at a gentle simmer.
- Preheat your oven to 400 degrees. Scoop your soup into oven-safe bowls, add a slice of bread (you can either pre-toast your bread and then add to let broil with the cheese, or place un-toasted in the broiler with the cheese) then a handful of shredded cheese.
- Broil or bake in the oven for 10 to 15 minutes until bubbly and melted. Top with fresh thyme and fresh cracked pepper.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Wow – this soup was so delicious! I followed it exactly, except I used red wine instead of white wine. I used a slice of swiss on top, with the bread toasted. I’ve been searching for a good vegetarian recipe that would give me the same dark color and rich flavor as the traditional french onion soup, and this hit the spot! Will definitely be adding this to my soup circulation this season. Thank you!
This sounds amazing! Thank you for trying it out Sara! Love this soup so much.
Hi there!
I was just wondering approximately how many servings this soup would make?? Dying to try it 🙂
About 2-3 full servings and around 4 appetizer soups!
Hi when you let it reduce for an hour is this supposed to be covered or without the lid? 🙂 thanks!!
Covered, but it’s okay if uncovered as well!
Turned out great.. Had to dilute it a little with water as the flavor was too strong. Thank you for this.
Utterly delicious soup and actually surprisingly simple to make. A bit labour intensive with all the stirring and monitoring but totally worth it. We don’t drink alcohol so used a mix of balsamic vinegar and water instead of wine. Worked well and added to dark caramel colour. Just made it for the second time in a week!
Hi Ruth, thanks so much for your amazing review! So happy you enjoyed!