This low-carb version of French onion soup is cheesy and flavorful. Make this healthy yet comforting soup in your slow cooker or Instant Pot.
It’s almost the new year which means the start of new years diets for most people. It’s no secret that low-carb / keto lifestyles are all the rage right now. Heck, I even wrote a low-carb cookbook (The Healthy Low-Carb Slow Cooker Cookbook shameless plug). Since French onion soup is my favorite soup, I decided to make a low-carb/keto version and I’m so glad I did; this soup is officially a last-minute addition to my Christmas menu. My Mom cooks most of the food but I’m allowed to provide an appetizer/starter and I know this will be a hit.
Let’s be honest, this is all about the cheese even though the majority of the time, the recipe cooks without it. What kind of cheese should you use? Gruyere is a personal favorite. Other suggestions include swiss or provolone.
Cook the onions along with a few other simple ingredients in your slow cooker or Instant Pot. When it’s done cooking is the fun part…adding the cheese. One batch of this soup filled 8 ramekins for me.
How much cheese to use? 1/4 cup? 1/2? I shredded my cheese down and added 1/3 cup on top of each ramekin before putting them under the broiler. If you want more cheese, add more. Want less? Use less. Keep in mind that since this is a low-carb version and there’s no bread to put the cheese on top of, the cheese will sink down into the ramekin. This may cause it to look like you don’t have as much cheese in your soup than you actually do. Not that there’s anything wrong with lots of cheese.
Broil the cheese until it’s nice & bubbling and starts to brown. This soup is best served warm while the cheese is stringy.Print
Slow Cooker/Instant Pot Low-Carb French Onion Soup (Keto)
- Prep Time: 10 minutes
- Cook Time: 4 hours
- Total Time: 4 hours 10 minutes
- Yield: 6-8 bowls 1x
- Add all the ingredients EXCEPT the cheese to the slow cooker. Stir to mix well.
- Cook HIGH 3-4 hours, LOW 6-8. Remove bay leaf.
- See FINAL STEP below
- Set Instant Pot to the high saute setting. Heat ghee/butter. When hot, add onion and garlic and cook, stirring occasionally, until tender, about 4-6 minutes.
- Pour in broth and using a wooden spoon scrape well the bottom of the Instant Pot to remove any bits that stuck to it, make sure you scrape it well to avoid burning during cooking. Add bay leaf, salt, pepper, and thyme.
- Close lid and seal valve. Set high pressure and cook for 25 minutes, natural release. Remove bay leaf.
- See FINAL STEP below
FINAL STEP (you will need ovenproof bowls)
Preheat broiler. Ladle the soup evenly into bowls & top evenly with shredded cheese. Arrange bowls on a large baking sheet. Place baking sheet carefully under the boiler and broil a few minutes or until cheese is melted and starting to brown slightly.
I used a 3.5-quart slow cooker for this recipe but you can easily doubled the recipe and use a 5 or 6-quart if you’re feeding a larger crowd.
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