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Vegetarian French Onion Soup Recipe

Vegetarian French Onion Soup

Wholesome Cove
This vegetarian French onion soup recipe swaps the traditional beef broth for a deeply savory vegetable base, while keeping everything else that makes the original so good. Six pounds of onions slowly caramelize until they turn jammy and golden brown, then simmer in a wine-and-herb broth that gets a boost from vegan Worcestershire sauce for that classic umami depth.
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Prep Time 20 minutes
Cook Time 1 hour 20 minutes
Total Time 1 hour 40 minutes
Course Soup
Cuisine French
Servings 6 servings
Calories 410 kcal

Equipment

  • Dutch oven - 5-quart or larger, heavy-bottomed
  • Oven-safe soup crocks - or ramekins
  • Mandoline slicer - for even onion slices (optional)
  • Sharp chef's knife
  • Wooden spoon
  • Ladle
  • Baking sheet
  • Kitchen torch - (optional, alternative to broiling)

Ingredients
  

  • 3 tablespoons unsalted butter - 45g
  • 2 tablespoons olive oil - 30ml
  • 6 large yellow onions - about 3 lbs or 1.4kg, thinly sliced
  • 1 teaspoon kosher salt - plus more to taste
  • 1 teaspoon granulated sugar
  • 4 cloves garlic - minced
  • ½ cup dry white wine - 120ml
  • 2 tablespoons all-purpose flour
  • 8 cups vegetable broth - 1.9L, or water mixed with vegetable bouillon base
  • 2 teaspoons vegan Worcestershire sauce
  • 2 bay leaves
  • 1 teaspoon fresh thyme leaves - plus more for garnish
  • ½ teaspoon black pepper
  • 1 French baguette - sliced into 1-inch rounds
  • 2 cups Gruyère cheese - 200g, shredded

For Serving

  • Fresh thyme leaves - for garnish

Instructions
 

  • Peel onions and slice thinly and evenly (about ⅛-inch thick) using a mandoline or chef's knife. Set aside.
  • Heat butter and olive oil in a Dutch oven over medium heat until butter melts and foams. Add onions and salt, stir to coat, reduce heat to medium-low, and cook for 35-40 minutes, stirring every 5-7 minutes, until softened and golden.
  • Sprinkle sugar over onions and continue cooking for 15-20 minutes, stirring more frequently, until onions are deep amber brown and jammy. Scrape up browned bits from the bottom.
  • Stir in garlic and cook for 1 minute until fragrant. Pour in wine and scrape the pot bottom to lift browned bits. Simmer for 2-3 minutes until wine is mostly reduced.
  • Sprinkle flour evenly over onions and stir constantly for 1-2 minutes to coat and remove raw flour taste.
  • Slowly pour in vegetable broth while stirring. Add Worcestershire sauce, bay leaves, thyme, and pepper. Bring to a gentle boil, then reduce heat and simmer uncovered for 25-30 minutes. Taste and adjust salt, remove bay leaves.
  • While soup simmers, preheat oven to 400°F (200°C). Arrange baguette rounds on a baking sheet and toast for 8-10 minutes, flipping halfway, until golden and crisp on both sides.
  • Switch oven to broil. Ladle hot soup into oven-safe crocks. Float 1-2 toasted baguette rounds on top and cover generously with shredded Gruyère. Place crocks on a baking sheet and broil for 2-4 minutes until cheese is melted, bubbly, and lightly browned. Let cool slightly before serving.

Notes

  • Don't rush caramelization: If onions are browning too fast, reduce heat. Patience is key to deep, sweet flavor.
  • Use a mix of onions: Swap one or two yellow onions for sweet onions to add a touch more sweetness.
  • Slice evenly: Uneven slices caramelize at different rates, so aim for uniform thickness.
  • Shred your own cheese: Pre-shredded cheese has anti-caking agents that prevent smooth melting.
  • Toast the bread: Untoasted bread turns mushy in the hot broth, so toast until crisp.
  • Make-ahead: Prepare the soup base up to 3 days in advance (without bread and cheese) and reheat before adding toppings.
  • Freezing: Freeze the soup base (without bread and cheese) in a freezer-safe container for up to 3 months.
  • Vegan option: Swap butter for olive oil and use a plant-based cheese alternative that melts well.
  • Gluten-free: Use a gluten-free flour blend and gluten-free bread for the topping.
  • No wine: Replace wine with an equal amount of additional vegetable broth and 1 teaspoon of apple cider vinegar for acidity.

Nutrition

Serving: 1BowlCalories: 410kcalCarbohydrates: 42gProtein: 14gFat: 19gSaturated Fat: 9gSodium: 980mgFiber: 4gSugar: 11g
Keyword caramelized onion soup, classic french onion soup, gruyere soup, meatless french onion soup, vegetarian french onion soup
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