Vegetarian French Onion Soup
I’ve been making this easy French Onion Soup every fall and winter for years! It’s so comforting and has the perfect balance of sweet, savory, carby, and cheesy goodness. After testing many variations, I’ve found that adding lentils helps thicken the soup, adds protein, and balances the textures. It makes for the BEST vegetarian French Onion Soup recipe!
Vegetarian Onion Soup Ingredients
For the Soup
- Olive Oil
- Yellow Onions, thinly sliced
- Brown Sugar
- Dry White Wine – Pinot Grigio and Sauvignon Blanc are great options. If you’re looking for a substitute, more vegetable broth with a splash of vinegar is the best alternative!
- Garlic
- Bay Leaves
- Vegetable Broth
- Salt/Pepper
- Vegetarian Worcestershire Sauce
- Cooked Lentils
For the Topping
- ROYO Low-Carb Artisan Bread – or bread of your choice. French bread, sourdough, gluten-free – there are so many great options for this easy soup!
- Vegetarian Gruyere Cheese – or cheddar cheese!
- Vegetarian Parmesan
- Fresh Thyme (Optional)
How to Make Vegetarian French Onion Soup
Making Vegetarian French Onion Soup is easy, and the key to the classic French onion soup flavor is giving the sliced onions some time to cook down. However, we’re still keeping this recipe as quick and easy as possible! Here’s how to make it:
- Over medium-high heat, cook the sliced onions with the oil in a Dutch oven for about 10 minutes.
- Add the salt and sugar, and keep cooking for 12-15 additional minutes.
- Add the wine, garlic, and bay leaves. Let cook for 5 minutes.
- Add broth, pepper, Worcestershire sauce, and cooked lentils. Stir and simmer over medium heat for 10 minutes.
- Toast the bread and break it up into large pieces.
- Remove the bay leaves, divide the soup into 4 bowls, and top with the bread pieces and cheese.
- Place under your broiler until bubbly, then top with a few fresh thyme leaves and serve!
Alternative Method: you can also skip the 4 individual bowls and just add the bread/cheese topping directly in the dutch oven, then broil!
Vegetarian French Onion Soup Recipe Tips
Onions – Onions need a little time to develop the depth of flavor, and a little sugar to help them caramelize. It helps to slice them as thinly as possible! White onions or sweet onions could be used as well.
Liquids – You can substitute the white wine for broth with a Tablespoon of apple cider vinegar. Beef stock can also be used instead of vegetable broth!
Make it Vegan – Use vegan cheeses and vegan Worcestershire sauce for a plant-based meal!
Large Pot Serving – Leave the soup in your Dutch oven, top with bread and cheese and broil the entire pot. Ladle each serving directly from the larger pot.
Storing – Let the soup cool completely, transfer it into an airtight container, and store it in the refrigerator for up to 3-4 days. You can also freeze the Vegetarian French Onion Soup for 1-2 months, but I suggest removing any bread and cheese topping before freezing. When reheated, add new toast and cheese and broil for the best texture and flavor!
Serving Vegetarian Onion Soup
This soup is absolutely perfect on its own, but it also makes a cozy, comforting addition to a simple weeknight dinner or even a small dinner party spread. I love serving it in individual oven-safe bowls for that bubbly, golden cheese top that feels like such a treat!
Here are a few of my favorite ways to serve it:
- On its own – It’s hearty and filling with the lentils, cheese, and toast. A complete, feel-good meal in a bowl!
- With a side salad – Something fresh and crisp like this Shaved Fennel Salad balances the richness of the soup so well.
- Paired with roasted veggies – Serve with a side of Roasted Carrots or Brussels Sprouts for extra fiber and flavor.
- As a starter – Great for cozy holiday dinners or small gatherings. Everyone loves the classic flavors!
French Onion Soup Vegetarian Storage Instructions
Refrigerator – Let the soup cool completely, then transfer it to an airtight container. Store in the fridge for up to 3-4 days.
Freezer – You can freeze the soup (minus the bread and cheese!) for up to 2 months. I recommend freezing it in individual portions to make reheating super simple.
Reheat – Warm the soup on the stovetop or in the microwave. Then, top with fresh toast and cheese and broil until bubbly again. So easy and still just as good as day one!
More Healthy Soup Recipes You’ll Love:
- Stuffed Cabbage Soup
- 4-Ingredient Potato Soup
- The BEST Crockpot Vegetable Soup
- Chicken Lemon Rice Soup
- Pumpkin Curry Soup
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French Onion Soup Recipe (Vegetarian)
Equipment
- Soup Bowls w/ Handles optional
Ingredients
- 2 Tablespoons olive oil
- 3-4 medium yellow onions (peeled and thinly sliced, about 4-5 cups sliced)
- 1 teaspoon salt
- 1 teaspoon brown sugar
- 1/2 cup dry white wine
- 3 teaspoons minced garlic
- 2 medium bay leaves
- 6 cups vegetable broth
- 1 teaspoon ground black pepper
- 2 teaspoons vegetarian Worcestershire sauce
- 2 cups cooked lentils (1 cup dry)
- 6 slices low-carb bread (toasted)
- 1 cup grated vegetarian Gruyere cheese
- 1/4 cup grated vegetarian parmesan
- fresh thyme (for garnish)
Instructions
- Cook the sliced onions in oil in a dutch oven over medium-high heat for about 10 minutes, stirring occasionally.
- Add the salt and sugar, then continue cooking for another 12-15 minutes.
- Add the wine, garlic, and bay leaves, cooking for another 5 minutes.
- Add the broth, pepper, Worcestershire sauce, and cooked lentils, simmer for another 10 minutes.
- Toast the bread and cut into pieces.
- Remove the bay leaves and divide the soup into 4 oven-safe bowls.
- Cover the top of each bowl with bread pieces of toast and cheeses.
- Broil at 400 degrees F for 5-7 minutes, or until the cheese is bubbly.
- Sprinkle with fresh thyme, serve, and enjoy!
Kier says:
I am going to make this tomorrow! Did you use red, brown, or red lentils?
Christine McMichael replied:
I used a mix. I hope you love the recipe!