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Two bowls with keto french onion soup

Keto French Onion Soup

Yummy Keto Cooking
This keto French onion soup will remind you of the classic bread-topped comfort food – but with far less carbs!
Prep Time 15 mins
Cook Time 50 mins
Total Time 1 hr 5 mins
Course Soup
Cuisine French
Servings 6 servings
Calories 392 kcal


For soup:

  • 5 tbsp butter
  • 2 large onions, sliced*
  • 2 tsp minced garlic
  • 1/3 cup white wine
  • 6 cups beef stock
  • 1 bay leaf
  • 2 sprigs thyme

For chaffles for topping:*

  • 3/4 cup shredded mozzarella
  • 3/4 cup shredded cheddar
  • 3 eggs

Cheese for topping:

  • 6 ounces gruyere, shredded


  • Add the butter to a large pot over medium heat. Add the onions and sauté for about 20-30 minutes, stirring frequently, until caramelized.
  • Add the garlic and cook for another minute. Pour in the wine and let it simmer for 2 minutes.
  • Stir in the beef stock, bay leaf, and thyme. Simmer for about 10-15 minutes.
  • While soup is cooking, make your chaffles. Mix together the mozzarella, cheddar, and egg. Spoon out enough batter to just fill a mini waffle maker. Cook until done. Repeat with the remaining batter (this should make about 6 small chaffles).
  • Discard the bay leaf and thyme, then ladle your soup into oven safe dishes. Place a chaffle on top of the soup and then add some shredded Gruyere cheese on top of that. Broil for 2-3 minutes until cheese is melted. Enjoy!


  • I recommend weighing your onions; you want to aim for around 1-1.25 pounds of onion for this recipe.
  • Only make as many chaffles as you need for serving today. For example, if you’re only making two servings today, only use 1/4 cup mozzarella, 1/4 cup cheddar, and one egg. That will make two chaffles.
Nutrition analysis (approximate per serving):
392 calories, 29 g fat, 16.5 g saturated fat, 1000 mg sodium, 9.7 g carbohydrate, 0.8 g fiber, 6 g sugar, 8.9 g net carbs, 22 g protein, Vitamin A: 20%, Vitamin C: 9%, Calcium: 52%, Iron: 6%
Keyword keto french onion soup, low carb french onion soup