This Guilt-Free French Onion Soup Is Causing Mass Addiction Among Keto Enthusiasts!

This Keto French Onion Soup is the ultimate low-carb comfort food. Caramelized onions swimming in a rich, savory broth, topped with gooey melted cheese—it’s the classic French favorite made keto-friendly.

By swapping out traditional bread with a keto-approved alternative or skipping it altogether, you can enjoy all the indulgent flavors while staying on track.

I’ll admit, the first time I attempted a keto version of French onion soup, I was skeptical. Would it still have that signature sweetness and depth of flavor? The answer: absolutely!

The key is to take your time caramelizing the onions to golden perfection, letting them release their natural sweetness. Every spoonful feels like a cozy embrace, perfect for chilly evenings or when you’re craving something rich yet wholesome.

Pair it with flavorful roasted vegetables for a hearty side or mushrooms for an elegant appetizer. This soup is a reminder that keto doesn’t mean giving up the dishes you love—it just means getting creative!

What’s your favorite way to top French onion soup? Share your variations in the comments!

Why You Will Be Hooked?

• Low-Carb Classic: All the deliciousness of traditional French onion soup, minus the carbs.
• Rich and Flavorful: Slow-cooked onions create an irresistible depth of flavor.
• Elegant Yet Easy: Perfect for a cozy dinner or an impressive starter.
• Customizable: Use your favorite keto-friendly bread substitute or enjoy it without.

Keto French Onion Soup Recipe

This classic French onion soup boasts caramelized onions in a rich, savory broth, topped with thyme-crusted croutons and gooey melted cheese. A comforting, hearty dish perfect for any occasion!

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 1 hour hr 20 minutes mins

Total Time 1 hour hr 35 minutes mins

Course Soup

Cuisine French

Servings 8

Calories 418 kcal

Equipment

• Large saucepan or stockpot
• Wooden Spoon or Spatula
• Knife and Cutting Board
• Oven-proof soup bowls
• Baking sheet
• Parchment paper
• Broiler or Oven

Ingredients

  

For the soup:

• 3 tablespoons olive oil
• 2 tablespoons butter
• 4 cups thinly sliced yellow onions
• 1 teaspoon kosher salt
• 1/2 teaspoon ground black pepper
• 1 teaspoon minced garlic
• 1/3 cup dry white wine
• 1 tablespoon fresh thyme leaves or 1 teaspoon dried
• 3 bay leaves
• 2 cups water
• 8 cups beef stock or vegetable stock for vegetarian
• 1 tablespoon Worcestershire sauce or for gluten free & vegetarian
• 1 tablespoon granulated erythritol
• 8 slices Swiss or Gruyere cheese to serve

For the toppers:

• 1 batch Easy Keto Dough
• 2 tablespoons fresh thyme leaves or 1 bunch of thyme springs

Instructions

 

For the Soup:

• Heat oil and butter in a saucepan over low-medium heat. Add onions, salt, and pepper, and cook for 30 minutes until golden brown.
  
• Stir in garlic and cook for 2–3 minutes.
• Add wine, thyme, and bay leaves. Simmer for 5 minutes until reduced by half.
  
• Add water, beef stock, Worcestershire sauce, and erythritol. Simmer uncovered for 30 minutes. Remove bay leaves and adjust seasoning.
  

For the Toppers:

• Preheat oven to 375°F. Shape dough into 8 discs, press thyme leaves on top, and bake for 15 minutes until golden.
  

To Assemble:

• Ladle hot soup into oven-proof bowls. Top with thyme croutons and cheese slices.
  
• Broil for 2–3 minutes until the cheese melts and turns golden. Serve hot.

Nutrition Info:

Tips that Will Help You Bring Best Results!

For the Soup

1. Caramelization Technique: Stir onions frequently during the 30-minute cooking to ensure even caramelization. If they stick to the pan, deglaze with a splash of water or stock and scrape up the browned bits to add depth of flavor.
2. Onion Variety: Mix yellow onions with a few red or sweet onions for a complex, layered sweetness.
3. Wine Substitution: If you don’t have white wine, a splash of dry sherry or apple cider vinegar diluted with water will add a similar acidity.
4. Stock Quality: Use homemade or high-quality beef or vegetable stock for the best flavor. If the stock is low-sodium, adjust the seasoning after simmering to prevent over-salting.
5. Thyme Control: Tie fresh thyme sprigs with kitchen twine for easy removal, leaving no stray leaves in the soup.

For the Keto Toppers

6. Perfect Dough: Chill the keto dough briefly before shaping if it becomes sticky. This makes it easier to handle.
7. Flavor Boost: Sprinkle a pinch of coarse sea salt or garlic powder on the toppers before baking for an extra layer of flavor.
8. Crispy Texture: For crunchier toppers, bake them slightly longer or let them cool on a wire rack to maintain crispness.

Assembly and Serving

9. Cheese Choice: Blend Gruyere with a touch of Parmesan for a nutty, sharp flavor that complements the soup. If you prefer mild cheese, Swiss is perfect.
10. Broiling Tip: Place the bowls on a baking sheet to make broiling safer and easier to handle. Watch closely to prevent burning.
11. Garnishing: Sprinkle freshly chopped parsley or a light drizzle of truffle oil on top before serving for a gourmet touch.

Try more of our recipes:

Red Cabbage Soup Recipe: Simple Comfort in a Bowl! Grilled Cheese and Tomato Soup Recipe: Simple and Satisfying! Brew-tiful Disaster: The Beer Cheese Soup That’ll Ruin All Other Comfort Foods The ‘Better Than Therapy’ Keto Soup That’s Healing Hearts (And Keeping Carbs Low!)