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Easy Vegetarian French Onion Soup Recipe

Easy Vegetarian French Onion Soup Recipe

Classic French onion soup made vegetarian with rich caramelized onions, veggie broth, and a gooey Gruyère toast cap. Cozy, savory, and perfect for chilly nights.
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Prep Time: 20 minutes
Cook Time: 1 hour 15 minutes
Total Time: 1 hour 35 minutes
Servings: 6

Ingredients
 

Main Ingredients

  • 2.75 lb yellow onions, thinly sliced about 6–7 medium
  • 2.5 tbsp unsalted butter
  • 1.5 tbsp olive oil
  • 1.25 tsp fine sea salt plus more to taste
  • 0.75 tsp granulated sugar helps onions caramelize
  • 2.5 tsp garlic, minced
  • 1.25 tbsp all-purpose flour light thickener
  • 0.75 cup dry white wine or dry sherry
  • 7.5 cup low-sodium vegetable broth preferably rich, dark style
  • 1 tsp dried thyme or 2 tsp fresh
  • 1 tbsp low-sodium soy sauce adds vegetarian umami
  • 0.5 tsp black pepper freshly ground
  • 9 oz baguette, sliced and toasted 1/2-inch thick
  • 9 oz Gruyère cheese, shredded or Swiss
  • 1 tsp sherry vinegar to finish, optional

Instructions

Preparation Steps

  • Warm butter and oil in a heavy pot over medium heat.
  • Add onions, salt, and sugar. Cook slowly, stirring often, until deep golden, 35–45 minutes.
  • Stir in minced garlic and cook 1 minute until fragrant.
  • Sprinkle in flour and cook 1 minute, stirring to coat the onions.
  • Deglaze with white wine, scraping up browned bits; simmer 2–3 minutes to reduce slightly.
  • Pour in vegetable broth. Add thyme, soy sauce, and black pepper. Simmer gently 20–25 minutes.
  • Toast baguette slices under the broiler until crisp; set aside. Heat broiler to high.
  • Ladle soup into broiler-safe bowls. Top with toasts and a mound of Gruyère. Broil until bubbling and browned.
  • Finish with a splash of sherry vinegar if using. Serve hot.

Notes

For extra depth, stir in 1 tsp white miso with the soy sauce or add sautéed mushrooms. To make it vegan, use plant butter and a meltable dairy-free cheese. The soup base keeps 4 days refrigerated; reheat gently and broil with fresh toast and cheese just before serving.
This recipe is an original creation inspired by classic Easy Vegetarian French Onion Soup Recipe flavors. All ingredient ratios and instructions are independently developed.