If you are looking for a hearty and delicious soup, this keto French onion soup is the way to go. It is full of flavor and feels fancy even though it doesn’t take much skill to make! At just 4g net carbs per soup serving, you can enjoy this classic French soup on any special occasion.
Have a special dinner coming up soon? I highly recommend serving this French onion soup recipe as a starter!
I love to make this soup if I am having company over and want to make something that looks and tastes like it took a lot of work. It’s one of those dishes that is so good, your guests won’t believe that it’s low-carb.
This easy French onion soup is also a family favorite because it is so rich and filling. Plus, you can add all kinds of toppings to it!
This easy French onion soup may look complicated at first, but it is really very simple to make. It takes a few ingredients, but they all come together beautifully.
Because this is a French onion soup, you are going to need plenty of onions! They are the star of this dish and will bring all of their amazing flavors with them.
For this soup recipe, I prefer to use white or sweet onions. Red onions tend to be too bitter in this dish.
You’ll want plenty of butter to cook your onions in. It provides fat which gives this soup sustenance as well as more depth and richness.
Brown Sugar Substitute
A brown sugar substitute is going to help this soup to really have a traditional French onion soup flavor. It adds that caramelized element and a touch of sweetness.
Tip: Check out this low-carb sugar guide to see which brands are my favorite!
Beef broth is the perfect broth option for this soup. The slight meaty element really brings the flavors of the dish together. If I don’t have time to make my own beef bone broth from scratch, I like to buy a few servings from Kettle & Fire!
Xanthan gum helps to thicken up this soup much like flour would, only it keeps the recipe keto-friendly.
White Cooking Wine
White cooking wine helps to add plenty of flavor to this soup and is a great complement to the broth.
Worcestershire sauce adds a punch of savory flavor, further enhancing the soup, giving it body and depth.
If you can’t find a sugar-free one at the store, try using my recipe for Worcestershire sauce from scratch!
Thyme and bay leaves are called for in the soup. The aromatic herbs bring an extra touch of freshness and brightness to this recipe.
Chopped parsley is used for a fresh, green garnish over the finished soup.
90 Second Bread
A single batch of 90-second bread (a.k.a. keto bread in a mug) can be turned into keto-friendly bread cubes to use as a topping.
Butter adds flavor and richness to the bread crumbs, while garlic powder seasons them to make the perfect finishing touch to a big bowl of keto French onion soup.
Gruyere cheese is also used for topping the soup. It’s a delicious cheese that will add flavor while bringing a cheesy element. Add it when the soup is hot so that it can melt.
You definitely want that cheese pull. It’s the best part!
Please note: Check out the recipe card at the bottom for a full list of ingredients used to make this low-carb recipe.
This recipe only takes a little forethought to whip up for a delicious and fancy dinner. For the full list of instructions, scroll down to the recipe card. First, here’s a step-by-step look at how to make this easy French onion soup.
Saute The Onions
Begin by placing your chopped onions in the butter over medium heat, sauteing for around 15 to 20 minutes, until they are caramelized. Then, add in the white cooking wine and simmer until it has reduced by half.
Add Ingredients And Simmer
Add in the rest of the soup ingredients and bring to a simmer for 15 minutes. Next, add in the xanthan gum, making sure to stir it thoroughly.
It should begin to thicken immediately.
Make The 90 Second Bread
While your soup is still simmering, quickly mix up a batch of 90-second bread. Once it’s cooked, cut it into cubes and toast them in the oven on a parchment-lined baking sheet.
Once toasted, brush the bread cubes with melted butter and garlic powder.
Assemble Keto French Onion Soup
Finish off your soup by pouring it into bowls and topping it with the bread cubes, chopped parsley, and gruyere cheese. Serve hot and enjoy!
🍽️ Serving suggestions
This keto French onion soup with toppings is very filling and could even be a meal all by itself. But, if you want to add sides, you have a bunch of options to choose from.
If you are wanting something fresh, this cold bacon cheddar broccoli salad will pair well with the warm, creamy soup.
Here are some of the most frequently asked questions I get from readers…
Can I add bacon to this French onion soup?
Yes, you definitely can add bacon to this delicious soup! In fact, bacon goes very well with these flavors and will only enhance the recipe.
How long does this soup last?
This soup lasts 3 to 4 days in the fridge. Make sure to store leftovers without any toppings and reheat the soup before adding the cheese on top.
How do I use up keto French onion soup leftovers?
Keto French onion soup is very versatile and can be added to other meals to use up leftovers! You could add this soup to your casseroles or reduce it with some chicken breasts.
The sky’s the limit to how you could use up leftovers of this yummy soup!
📚 Related recipes
If you liked this easy French onion soup recipe, you should try these other low-carb soup recipes. They are all easy to make and taste just right on a blustery day!
- Cheesy Broccoli Cauliflower Soup With Sausage is a rich soup full of tasty cheese and hearty flavors!
- Keto Crockpot Cheeseburger Soup is another soup that will fill you up any day of the week. It tastes like traditional cheeseburger soup without all of the carbs.
- Unstuffed Cabbage Soup Recipe is a knockoff of the traditional meal of stuffed cabbage, only this soup is made much faster and tastes just as good!
- Broccoli Cheese Soup With Cheddar is a rich and creamy soup that is filling and deliciously cheesy.
- Keto Vegetable Soup is a simple recipe that is full of veggies in an amazing-tasting broth.
Keto French Onion Soup
- 2 medium onions sliced
- 4 tablespoons butter
- 3 teaspoons brown sugar substitute
- ¼ teaspoon xanthan gum
- 6 cups beef broth
- ¼ cup white cooking wine
- 1 teaspoon Worcestershire sauce
- 1 teaspoon chopped fresh thyme
- 2 bay leaves
- 1 batch 90 second bread
- 1 tablespoon butter melted
- ½ teaspoon garlic powder
- 1 cup grated gruyere cheese
- chopped parsley for garnish
- Add the 4 tablespoons. Butter and the onions to a saucepan over medium heat. Sauté for 15-20 minutes until softened and caramelized.
- Add in the white cooking wine and saute until the liquid is reduced by half.
- Add in the brown sugar substitute, beef broth, Worcestershire sauce, fresh thyme and bay leaves. Simmer for 15 minutes.
- Prepare one batch of 90 second bread and cut it into cubes. Place the cubes on a parchment lined baking sheet and broil them until toasted.
- Brush the bread cubes with the melted butter and sprinkle with the garlic powder.
- Sprinkle the xanthan gum into the soup, and simmer until thickened.
- Serve topped with the toasted bread cubes and shredded gruyere cheese with chopped parsley for garnish.
Array ( [calories] => 257 [carbohydrates] => 6 [protein] => 12 [fat] => 20 [saturated_fat] => 11 [polyunsaturated_fat] => 1 [monounsaturated_fat] => 5 [trans_fat] => 1 [cholesterol] => 80 [sodium] => 1130 [potassium] => 217 [fiber] => 2 [sugar] => 2 [vitamin_a] => 520 [vitamin_c] => 3 [calcium] => 251 [iron] => 1 )
Note on Nutritional Information
Nutritional information for the recipe is provided as a courtesy and is approximate only. We cannot guarantee the accuracy of the nutritional information given for any recipe on this site. Erythritol carbs are not included in carb counts as it has been shown not to impact blood sugar. Net carbs are the total carbs minus fiber.
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