Go Back Email Link
–+ servings
Bowl of vegetarian French onion soup topped with a slice of melted cheese and bread, with a spoon resting inside, on a striped napkin.
Print Recipe
5 from 1 vote

Vegetarian French Onion Soup

A rich and savory vegetarian French onion soup made with deeply caramelized onions and a flavorful meatless broth. Finished with toasted bread and melted cheese for a classic, comforting bowl.
Prep Time10 minutes
Cook Time1 hour
Total Time1 hour 10 minutes
Course: Appetizer, Main Course, Soup
Cuisine: French
Diet: Gluten Free, Vegetarian
Servings: 4 servings
Calories: 369kcal
Author: Kristen Wood

Ingredients

  • 3 tablespoons unsalted butter
  • 2 tablespoons extra virgin olive oil
  • 5 large yellow onions thinly sliced
  • 1 teaspoon salt
  • ½ teaspoon ground black pepper
  • 2 teaspoons fresh thyme leaves or 1 teaspoon dried
  • 1 tablespoon all-purpose flour use gluten free if necessary
  • ½ cup dry white wine or 2 tablespoons apple cider vinegar + 6 tablespoons vegetable broth
  • 6 cups vegetable broth
  • 1 tablespoon tamari or soy sauce use gluten-free if necessary
  • 1 bay leaf
  • 6 slices baguette use gluten free if necessary
  • 1 ½ cups grated Gruyère or dairy-free cheese alternative, use rennet-free Gruyère if vegetarian (see notes)
US Customary - Metric

Instructions

  • Heat the butter and olive oil in a large pot over medium-low heat. Add onions and salt, cooking slowly for 40-50 minutes, stirring often, until deeply golden and caramelized.
    Sliced onions cooking in oil in a pan, stirred with a blue spatula—the perfect start for a delicious vegetarian French onion soup.
  • Stir in the thyme, pepper, and flour, cooking for 1 minute.
    A blue spatula mixing cooked onions and powder in a white pan with some oil, the perfect base for vegetarian French onion soup.
  • Deglaze the pan with white wine if using, or add the vinegar-broth mixture, scraping up any browned bits. Simmer until mostly reduced.
    A blue spatula stirs caramelized onions in a white pan, creating a golden, saucy mixture perfect as the base for vegetarian French onion soup.
  • Add the vegetable broth, tamari, and bay leaf, then bring to a gentle simmer for 20 minutes. Remove the bay leaf.
    A close-up of reddish-brown broth with oil droplets and a single bay leaf floating on the surface, showcasing a warm bowl of vegetarian French onion soup.
  • Preheat the broiler and arrange baguette slices on a baking sheet. Toast until golden on both sides. Ladle the soup into oven-safe bowls, top each with a toasted baguette slice and plenty of Gruyère, then broil until cheese is melted and bubbling.
    White bowl of vegetarian French onion soup with shredded cheese, thin noodles, and a slice of toasted bread on parchment paper.
  • Serve hot with extra thyme sprinkled on top. Enjoy!
    A bowl of French onion soup topped with melted cheese and herbs, with a spoon resting inside.

Video

Notes

My favorite vegetarian (rennet-free) Gruyère comes from Whole Foods (their 365 brand!).
Storage and Reheating
Store cooled leftover soup (without baguette or cheese topping) in an airtight container and keep it in the refrigerator for up to 4 days. You can also freeze the vegetarian French onion soup for up to 3 months.
To reheat, you can warm the soup on the stove (medium heat) or in the microwave. Stir occasionally and avoid boiling to preserve the flavors. Once hot, serve in bowls, top with toasted baguettes and grated Gruyere cheese, then broil them until golden and bubbly.

Nutrition

Serving: 1serving | Calories: 369kcal | Carbohydrates: 43g | Protein: 7g | Fat: 17g | Saturated Fat: 7g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 8g | Trans Fat: 0.3g | Cholesterol: 23mg | Sodium: 2548mg | Potassium: 303mg | Fiber: 4g | Sugar: 12g | Vitamin A: 1066IU | Vitamin C: 12mg | Calcium: 95mg | Iron: 2mg
QR Code linking back to recipe