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Keto French Onion Soup

Delicious keto French onion soup is high protein and packed with flavor. It’s topped with gluten-free garlic crostini and gruyere cheese. This low carb comfort food will have you dreaming of Paris.

Two bowls of keto French onion soup overhead

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Just imagine…

For just a moment close your eyes. In your mind’s eye, imagine yourself at a small table in front of a café on the Champs-Elysées in Paris. To your left and down the street a ways is the magnificent Arc de Triomphe.

Perhaps you’re wearing a tan beret, black jeans and blouse, with a well-cut tan wool blazer. There’s a slight chill in the air, and you breathe it in with delight.

As you ponder Napoléon and his armies, two dessicated reddish leaves catch your eye as they fall from a nearby tree and land on the table next to yours. You smile as the sunlight catches your face.

Just then a smart-looking waiter magically appears at your side and presents you with the fall favorite, soup à l’oignon. Bien sûr, you say “merci” and enjoy the day and your meal.

Why soup à l’oignon? Well, you’re in Paris! There’s no need to call the classic French onion soup. 

Wasn’t that a nice little escape? Shall we invoke the senses of smell and taste now to lead us to Paris as well? Why not?

Why not, indeed! Let’s take a trip lead by this delicious keto French onion soup. On y va!

Keto French Onion Soup is a traditional delicious comfort food gone low carb. Topped with a gluten-free crostini and gruyere cheese, close your eyes and you're in a French cafe. #ketosoup #ketorecipes #ketofrenchonionsoup

While I think you’ll love my super helpful tips and fun stories, I also realize we are sometimes pressed for time and just need a good recipe!

Scroll down to the bottom of the page for the printable recipe or PIN it here for later!

A walk about Paris will provide lessons in history, beauty, and in the point of life.

– Thomas Jefferson

🧅 Are onions good for a keto diet?

If we take a look at the common and steadfast onion, there are many points to consider. First, what are the health benefits? Second, do onions help or hinder a keto diet? Third, do the benefits outweigh any negatives?

First off, let’s consider the health benefits of onions. They are full of nutrients, so are high in vitamins and minerals, especially C, B, and potassium. 

They have potent anti-inflammatory properties and have powerful antioxidents. In fact, they contain over 25 different varieties of flavonoid anti-oxidents (source). Some studies show these may protect against heart disease, certain cancers and diabetes.

Onions are considered allium vegetables, as are garlic, leeks, and chives. They are believed to contain cancer-fighting properties. Win!

On the other hand, are onions good for a keto diet? Onions have more carbs than some other vegetables and are higher in natural sugars. These facts don’t prevent me from eating onions. However, they do limit the amount I consume.

It’s just like with most things. You don’t want to go overboard with anything. For me, I’ve found they work with my diet in moderation. 

I’ve heard all my life to eat your onions! They’re good for you! Let’s just say I haven’t always loved them. But I do so now.

Thinly sliced onions for low carb French onion soup. #onions #frenchonionsoup #ketosoup

🍽 Equipment

TO MAKE KETO FRENCH ONION SOUP YOU’LL NEED: 

Keto French Onion Soup from the side with gruyere and garlic crostini #ketosouprecipes #ketorecipes #lowcarbsoup

🥘 Ingredients

  • onions
  • butter
  • MCT oil or other oil (e.g. avocado or coconut oil)
  • salt
  • pepper
  • sweetener (such as Swerve Confectioners)
  • beef bone broth
  • dried ground thyme
  • bay leaves
  • Gruyère, Swiss, or provolone cheese (sliced)
  • dry sherry
  • garlic parmesan keto biscuits

🔪 Instructions

HOW TO MAKE KETO FRENCH ONION SOUP

To begin, get out the ingredients and pans, etc. so everything is easily accessible. Let’s start out by making the soup.

First, melt three tablespoons of butter in a large soup pot or Dutch oven. Then add in the thinly sliced onions and oil. Cook them on a medium-high heat, stirring occasionally until soft, or about 15 minutes.

Onions in the pot to soften

Second, add the sweetener, salt, and pepper. Now, this is where patience comes into play!

Continue to cook the onions, stirring every few minutes for 30-40 minutes. They should be beautifully browned and caramelized.

Onions beginning to caramelize

💭 Top tip

If they start to brown too quickly, turn down the heat. Be patient and let them cook and caramelize.

Next, add in one and a half cups of beef bone broth. If you wish to stick more to a traditional recipe, use a dry white wine instead of bone broth at this point. However, know that this will increase sugar and carbs slightly.

Once the liquid is in, turn up the heat to high. Boil it all for 8-10 minutes until the liquid reduces. Be sure to stir it frequently so as not to burn the onions.

Now add the remaining bone broth and thyme and bay leaves. If you have fresh thyme you can used about 10 sprigs of it and put it and the bay leaved in a small cheesecloth tied for easy removal later. I rarely have fresh thyme so let it disperse in the soup.

Bring the mixture to a boil then reduce to a simmer until the soup’s slightly thickened. Then remove the pot from the heat and add two more tablespoons of butter. Because, why not? Yum. 

Lastly, season to taste as you like.

Gluten-free garlic crostini (or crouton)

Now to make the classic toasts, croutons, or crostini, whatever you prefer to call them, to top the soup.

I like to use my garlic parmesan keto biscuits recipe, but you can use any gluten-free keto bread you wish.

Slice the biscuits or other gluten-free bread, in about ⅙ of an inch slices, and place them on a baking tray. If you use different gluten-free bread, not packed with garlic flavor like my keto biscuits, rub each slice with a cut clove of garlic before broiling.

Gluten-free garlic parmesan crostini, or toasts

Next, turn the oven on low broil and put the baking tray with the bread slices in for about five minutes. Watch them until the edges begin to brown. Then, remove the croutons from the oven and let them cool completely.

👩‍🍳 Assembly

How to top the keto French onion soup

Now that you have all the required parts, we’re ready to assemble!

First, preheat an oven to broil on high. If you wish, place a teaspoon of sherry in the bottom of each French onion soup crock or bowl.

Then, use a ladle to divide the soup into six French onion soup crocks, ramekins, or regular bowls. Top each with two garlic crostini (or croutons) and a slice of cheese.

Gruyère cheese is traditional and delightfully creamy when it melts if you like it. However, sometimes it can be hard to find or pretty expensive. In that case, you could use Swiss or provolone cheese instead.

I’ve found grated cheese can be used but tends to sink and not create that lovely top we expect to see on French onion soup. Therefore, a slice of cheese can make a good seal for the top.

Keto French Onion Soup overhead with gruyere and garlic crostini #ketosouprecipes #ketorecipes #lowcarbsoup

Now, place the crocks or bowls on a baking sheet. Carefully put the pan and soup in the oven or broiler for three to four minutes. Truly, my advice is to watch it until the cheese begins to bubble and brown, but not to burn. 

Lastly, remove them from the oven, cool for 2-3 minutes, and serve! You might want to turn on some laid-back French café music. Also, don’t forget to pull out your beret! 

Bon appétit!

Bite of keto French onion soup with gruyere cheese and garlic crostini. #ketorecipes #ketosouprecipes #lowcarbsoups

What are your favorite French foods?

Are you a fan of French cuisine? I totally enjoy all things French and need any excuse to hop on a plane. While at home I stick to keto and low carb recipes, but I admit when traveling I don’t say no to the local bakeries and traditional dishes.

Do you have any favorite French dinners or desserts you’d like to see undergo a keto makeover? I’d love to get your suggestions and give them a go! Just comment with your idea in the comments section below.

I hope you love this recipe, and it takes you back to Paris or Toulouse or wherever you may have a memory of it!

Pin the recipe here:

Delicious keto French onion soup is high protein and packed with flavor. This low carb comfort food will have you dreaming of Paris. Friendly for a keto diet and topped with gluten-free garlic crostini and  gruyere cheese. Yum. #ketosoups #ketodietrecipes #lowcarbdinner

Follow me on Instagram @explorermomma and tag me in your food pictures! I can’t wait to see what you make!

If you LOVE this recipe please consider giving it a five-star rating in the review area below!

🍲 Keto soup recipes

  1. Creamy Keto Italian Sausage Soup
  2. Keto Thai Coconut Soup
  3. Low Carb Chicken Mushroom Soup
  4. Keto Taco Soup

📖 Recipe

Keto French Onion Soup overhead with gruyere and garlic crostini #ketosouprecipes #ketorecipes #lowcarbsoup

Keto French Onion Soup

Yield: 6
Prep Time: 10 minutes
Cook Time: 50 minutes
Total Time: 1 hour

The intricate flavor of low carb French onion soup topped with gluten-free garlic toast and bubbly Gruyère cheese. This one will take you back to that little café under the Eiffel Tower.

Ingredients

  • 4 medium onions, thinly sliced
  • 5 tbsp butter (separated)
  • 1 tbsp MCT oil (or coconut or avocado oil)
  • 1 tsp salt
  • ½ tsp black pepper
  • 1 tbsp powdered sweetener, (such as Swerve Confectioners)
  • 1½ cups beef bone broth (or dry white wine)
  • 6 cups beef bone broth
  • 1 tsp ground thyme
  • 2 bay leaves
  • 4 oz Gruyère, Swiss, or provolone cheese, (sliced)
  • 2 tsp dry sherry
  • 3 garlic parmesan keto biscuits

Instructions

  1. Melt three tablespoons butter in a large Dutch oven. Add in the thinly sliced onions and oil. Cook on medium-high heat until soft or about 15 minutes.
  2. Add the sweetener, salt, and pepper. Continue cook, stirring every few minutes for 30-40 minutes, or until beautifully browned and caramelized. If it starts to brown too quickly, turn down the heat.
  3. Add the one and a half cups of beef bone broth (or dry white wine) and turn up the heat to high. Boil it all for 8-10 minutes until the liquid reduces. Stir it frequently so as not to burn the onions.
  4. Add the remaining bone broth and herbs. Bring to a boil then reduce to a simmer until it's slightly thickened. Remove the pot from the heat and add two more tablespoons of butter. Season to taste.

Garlic Crostini

  1. Slice the biscuits about ⅙ of an inch and place on a baking tray. If you use different gluten-free bread, rub each slice with a cut clove of garlic before broiling.
  2. Turn the oven on low broil and put the slices in for about five minutes, or until the edges begin to brown. Remove from the oven and let cool completely.

Top and Serve the Soup

  1. Preheat an oven to broil on high.
  2. Use a ladle to divide the soup into six French onion soup bowls or ramekins. Top each with two garlic crostini (or toasts) and a slice of cheese. Grated cheese can be used but tends to sink.
  3. Place the bowls on a baking sheet and put in the oven or broiler for three to four minutes or until the cheese begins to bubble and brown. Watch it so as not to burn.
  4. Remove from the oven, cool for 2-3 minutes and serve.

Notes

Nutrition Facts

Servings 6.0 Amount Per ServingCalories 264  Total Fat 18 g Saturated Fat 11 g Monounsaturated Fat 5 g Polyunsaturated Fat 1 gTrans Fat 0 g Cholesterol 46 mg Sodium 939 mg Potassium 134 mg Total Carbohydrate 7 g Dietary Fiber 1 g Sugars 3 g Protein 19 g Net Carbohydrate 6 g

*Nutrition Facts per MyFitnessPal.com. For most accurate facts, calculate your own with the exact ingredients you use in the recipe.

**Nutrition facts do not include the garlic crostini as it varies depending on the gluten-free bread used.

Nutrition Information:
Yield: 6
Amount Per Serving: Calories: 264Unsaturated Fat: 0g

Did you make this recipe?

Tag @explorermomma on Instagram and hashtag it #explorermomma. Thanks a bunch!

NUTRITION DISCLAIMER

Please be aware I am not a medical specialist or nutritional professional. On this blog, I share recipes and what works for me. Please do not take anything on this blog as medical advice and always consult with your doctor before starting any diet or exercise program.
 
I use MyFitnessPal.com to calculate nutrition facts as a courtesy to my readers, and I remove erythritol from the final carb count and net carb count because it does not affect my own blood glucose levels.
 
This is as accurate as possible, but it’s best to independently calculate nutritional information on your own with the specific ingredients you use.
 
I expressly disclaim any and all liability of any kind with respect to any act or omission wholly or in part in reliance on anything contained in this website.

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