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vegetarian French onion soup

Vegetarian French Onion Soup

This cozy vegetarian French onion soup skips the wine and delivers deep flavor from caramelized onions, thyme, and umami-rich broth—topped with crusty bread and melty cheese.
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Prep Time 15 minutes
Cook Time 1 hour 15 minutes
Total Time 1 hour 30 minutes
Course dinner, Soup
Cuisine French, Vegetarian
Servings 4
Calories 380 kcal

Equipment

  • Large Dutch oven or soup pot
  • Wooden spoon
  • Chef's knife
  • Oven-safe soup bowls or ramekins
  • Baking tray

Ingredients
  

  • 3 lbs yellow onions Thinly sliced into half moons
  • 4 tbsp olive oil For caramelizing
  • 2 tbsp vegan butter Adds richness and creaminess
  • 1 tsp sugar Helps onions caramelize
  • 1½ tsp sea salt Adjust to taste
  • 4 garlic cloves Minced
  • 8 cups vegetable broth Use dark flavorful broth if possible
  • 1 tbsp balsamic vinegar Adds deep flavor without wine
  • 2 tsp tamari or soy sauce Optional, boosts umami
  • 1 tbsp vegan Worcestershire sauce Check for fish-free version
  • 2 bay leaves Earthy depth
  • 1 tbsp fresh thyme Or 1 tsp dried thyme
  • ½ tsp black pepper Fresh ground preferred
  • 4 slices French bread Use gluten-free if needed
  • 1 cup Gruyère cheese Or vegan cheese of choice

Instructions
 

Caramelize the onions

  • In a large Dutch oven, heat olive oil over medium heat. Add the onions and stir frequently for 20 minutes. Add vegan butter and continue cooking for another 20–25 minutes, reducing heat if needed. Onions should be golden brown and jammy.

Layer in flavor

  • Stir in sugar, salt, and garlic. Cook 5 more minutes. Add balsamic vinegar and tamari to deglaze the pan, scraping up all those rich brown bits.

Simmer the soup

  • Pour in vegetable broth, Worcestershire sauce, bay leaves, thyme, and pepper. Stir well. Bring to a gentle simmer, cover partially, and cook for 30 minutes to let flavors marry.

Toast the bread

  • While the soup simmers, place bread slices on a baking sheet. Toast at 400°F (200°C) for 10 minutes, flipping halfway until crisp and lightly browned.

Assemble and broil

  • Ladle hot soup into oven-safe bowls. Top each with a toasted bread slice and a generous handful of shredded cheese. Place bowls on a baking tray and broil for 3–5 minutes until the cheese is melted and bubbly. If you're skipping broiling, just melt the cheese onto the toast and float it in the bowl.

Notes

Vegan Option: Choose plant-based cheese and double-check your Worcestershire.
Gluten-Free: Use a gluten-free baguette or serve with our gluten-free biscuits.
Storage: Keep soup refrigerated for up to 4 days. Reheat gently; add fresh toast and cheese before serving.
No Broiler? Toast and melt the cheese on bread slices separately, then top the soup.