Vegetarian French Onion Soup

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Have you heard of my fan club? “The Sweet Peas” (as they call themselves) are a group composed of my dear friends, Allie and Meghann. These two are always sending love and support for everything on Sweet Pea Living. As a thank you for their unwavering positivity and encouragement, I had them over for dinner a few weeks ago. Somehow I knew exactly what I wanted to make for them. After all, what’s better than a simmering pot of French Onion Soup? Almost nothing, that’s what!

This recipe has quickly become a favorite of ours (I’ve made it three times in the last three weeks… not kidding) and I hope that you enjoy it as much as we do! When you make it, be sure to tag and use the hashtag #sweetpealiving on Instagram.

Vegetarian French Onion Soup

Sweet Pea Living
A simmering, mouth-watering soup packed with umami flavor and a feisty crushed red pepper kick!
5 from 1 vote
Prep Time 10 mins
Cook Time 50 mins
Total Time 1 hr
Course Main Course, Soup
Cuisine French
Servings 4 people
Calories 531 kcal


  • 4 tbsp butter unsalted
  • 3 white onions sliced thinly
  • 3 red onions sliced thinly
  • 2 cups cremini mushrooms chopped
  • 4 cloves garlic minced
  • 2 tbsp flour
  • 2 bay leaves
  • 2 tsp fresh thyme
  • 1 tsp crushed red pepper flakes*
  • 1 tsp salt
  • ½ tsp black pepper
  • ¼ cup balsamic vinegar
  • ½ cup dry red wine
  • 4 cups vegetable broth
  • crusty bread sliced into bite-sized pieces
  • Parmesan cheese


  • In a large soup pot, melt the butter over medium-low heat.
  • Add the onions, mushrooms, and garlic. Saute until all the onions and mushrooms are soft and brown.
  • Add the flour. Stir in a figure-eight motion until the flour has been absorbed by the onions and becomes sticky.
  • Add bay leaves, thyme, crushed red pepper flakes, salt, black pepper, balsamic vinegar, red wine, and vegetable broth. Simmer for 15-20 minutes over medium heat.
  • Remove bay leaves.
  • Place a few bread pieces at the bottom of individual-serving oven-safe bowls.**
  • Use a ladle to fill each bowl with soup. Top with Parmesan cheese.
  • Broil for 3-5 minutes, until cheese is brown and crispy.
  • Serve hot and enjoy!



* Add less if you are sensitive to heat.
** Place the bowls on a baking sheet to avoid any spilling in your oven!


Sodium: 1274mgSugar: 9.3gFiber: 2.6gCholesterol: 54mgCalories: 531kcalSaturated Fat: 13gFat: 27gProtein: 14gCarbohydrates: 42g
Keyword Cheese, Onion, Soup
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