Vegetarian French Onion Soup Recipe

With over 30 5-star ratings, this is my go-to French Onion Soup recipe that I honestly think is the best! Made with hearty lentils, sweet onions, and topped with bread and Gruyere cheese, this cozy soup has that toasty bubbly cheesy crust on top that’s SO good. I love how easy this recipe is to make!

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 (opens in a new tab)
• Vegetable Broth
• Salt/Pepper
• Vegetarian Worcestershire Sauce (opens in a new tab)
• Cooked Lentils

For the Topping

• ROYO Low-Carb Artisan Bread (opens in a new tab) – 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:

1. Over medium-high heat, cook the sliced onions with the oil in a Dutch oven for about 10 minutes.
2. Add the salt and sugar, and keep cooking for 12-15 additional minutes.
3. Add the wine, garlic, and bay leaves. Let cook for 5 minutes.
4. Add broth, pepper, Worcestershire sauce, and cooked lentils. Stir and simmer over medium heat for 10 minutes.
5. Toast the bread and break it up into large pieces.
6. Remove the bay leaves, divide the soup into 4 bowls, and top with the bread pieces and cheese.
7. 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, (opens in a new tab) 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, (opens in a new tab) 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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