This Miso French onion soup is a complete revamp of an old recipe I’ve had on the blog for years, and I’m excited to make it for you now that I can have gluten and dairy again. I wanted to keep that classic cozy, caramelized-onion comfort but deepen the flavor in a way that felt more layered and modern, and the miso does exactly that. It transforms the broth into something richer, more complex, and totally crave-worthy while still honoring everything we love about the original. With slices of sourdough bread and melted gruyere cheese on top, every bite is so incredible and so addictive.
Wow this was good! Definitely the best french onion soup i’ve ever had.
Why You Will Love This Miso French Onion Soup
- The miso competes for star status and adds deep, savory umami without overpowering the onions’ sweetness.
- This great recipe is impressive enough for guests but easy enough for a weeknight dinner.
- That cheesy, golden top is pure comfort food magic.
- Customize this to be dairy-free and gluten-free in two easy steps.
- Although it’s not quick, it’s easy and well worth the effort.
Ingredients You Will Need
- Butter: Adds richness and depth to the onions as they caramelize. You can also use olive oil or avocado oil.
- Yellow Onions: Yellow onions are my first choice; slice them thinly and evenly. You can also use sweet onions.
- Salt: Enhances onion flavor and helps them break down as they caramelize.
- Fresh Garlic: Finely mince the garlic with a microplane grater or a garlic press to release all the delicious flavor.
- Dried Thyme: Adds an herbaceous, earthy flavor to complement everything else. Fresh thyme also works great just be sure to triple the amount to compensate for the concentrated flavor of dried.
- White Wine: Brings acidity and brightness to balance the rich broth. You’ll want a dry white wine like Chardonnay, Pinot Grigio, or Sauvignon Blanc.
- Beef Broth: Forms the savory, flavorful base of the soup. You can also use beef stock.
- White Miso Paste: Adds deep umami and subtle saltiness to the broth. So delicious!
- Sourdough Bread: Its sturdy and tangy slices are perfect for the toasted topping.
- Gruyere Cheese: Melts beautifully with a nutty, slightly sweet flavor.
Kitchen Tools You Will Need
- Large Pot or Dutch Oven
- Cutting Board
- Sharp Knife
- Wooden Spoon
- Small Oven-Proof Bowls
- Soup Ladle
Be Patient
Be patient! Low and slow onions are non-negotiable for real depth and sweetness. Add a splash of water and lower the heat if your onions start to brown or burn too quickly.
How to Make This Miso French Onion Soup
- Melt the butter on medium heat. Add in the sliced onions and sprinkle with salt. Place the lid on the pot and leave the onions to cook until they begin to soften and then remove the lid and leave to cook until the onions are caramelized.
- Once the onions are caramelized, add the garlic and thyme and stir. Cook for 2 minutes, then add the white wine and cook the onions until most of the liquid has evaporated.
- Add the beef broth and miso paste and bring to a simmer. Let the soup simmer for 10 minutes, then stir to ensure the miso is fully blended into the broth.
- Arrange small bowls on a baking sheet, ladle the soup into each bowl, and top with a slice of bread, then sprinkle grated cheese on top.
- Turn the oven on to broil. Place the assembled soups in the oven and broil until the cheese is melted, bubbly, and golden brown. Watch carefully to ensure that the cheese doesn’t burn.
enhance the flavor
For an added layer of richness, lightly toast and butter your bread before adding it on top of the soup.
How to Modify
- If you prefer, white onions will work wonderfully. I don’t recommend using red onions, though.
- Chicken broth or chicken stock will also work for this, and you can add a splash of balsamic vinegar to add depth.
- Use French bread, Italian bread, or a baguette in place of sourdough. Toasted bread is a great idea, too, because it will hold up a bit more.
- Swiss Cheese and Provolone are great cheese options in place of the Gruyere.
- Add an earthy kick with a bit of freshly ground black pepper at the end.
Dietary Customizations
- Vegan/Vegetarian: Use vegetable broth for a delicious vegan French onion soup.
- Dairy-Free: Use vegan butter or olive oil, and try your favorite vegan cheese, like Follow Your Heart or Daiya.
- Gluten-Free: Try gluten-free sourdough or your favorite gluten-free bread.
Serving Suggestions
For a soup and salad meal, try my Wedge Salad, Shaved Zucchini Salad, or a Honey Mustard Chicken, Bacon, and Avocado Salad for a salad with protein.
And if you love pasta and soup together, you can’t go wrong with Pasta al Limone, Truffle Mushroom Pasta, or Miso Cacio e Pepe.
Common Questions
Miso adds deep umami and savory complexity without overpowering the classic sweet onion flavor.
White miso is best and my first choice for a balanced, slightly sweet flavor. Darker miso will make the soup bolder and saltier.
Absolutely! The soup base actually tastes even better the next day. Just add the bread and cheese before serving.
Store the soup base separately from the bread and cheese. After bringing to room temperature, store in an airtight container in the fridge for up to 4 days. Reheat gently on the stovetop over medium-low heat.
Turn on the sauté and cook onions in butter. This will still take 20–30 minutes, so stir occasionally and let them brown properly. Don’t rush it! Add thyme and garlic and cook briefly. Deglaze with white wine and scrape up all the browned bits, and add broth. Pressure cook for 5 minutes, then quick-release. Stir in the miso. Do not pressure cook after adding miso. Stir to ensure the miso is fully blended into the broth, then ladle into oven-safe bowls, top with bread and cheese, and broil.
Caramelize the onions on the stovetop first (this is essential). Transfer onions to the slow cooker and add remaining ingredients except miso. Cook on Low for 6–8 hours or High for 3–4 hours. Stir in miso during the last 15–20 minutes.
More Soup Recipes You Will Love
- Cabbage and Chicken Soup
- Pasta e Fagioli
- Egg Drop Soup
- Creamy Tomato Soup
- Pesto Chicken and Tortellini Soup
If you make this Miso French Onion Soup, let me know in the comments section below. I would love to hear what you think or take a photo and tag me (@everylastbite_) on Instagram. I love seeing your photos!
Miso French Onion Soup
Ingredients
- 3 tbsp butter
- 4 yellow onions thinly sliced
- ½ tsp salt
- 3 cloves garlic minced
- 1/2 tsp dried thyme
- ½ cup white wine
- 4 cups beef broth
- 2 tbsp miso paste
- 4 slices sourdough bread
- ⅔ cup grated gruyere cheese
Instructions
- Melt the butter in a large pot on medium heat. Add in the sliced onions and sprinkle with salt. Place the lid on the pot and leave the onions to cook for 10-15 minutes until they begin to soften and then remove the lid and leave to cook for an additional 40 minutes, stirring occasionally until the onions are caramelized. If the onions begin to brown/burn too quickly add a splash of water and lower the heat.
- Once the onions are caramelized add in the minced garlic and thyme and stir. Cook for 2 minutes and then add in the white wine, increase the heat to medium high and leave the onions to cook until most of the liquid has evaporated.
- Add the beef broth and miso paste and bring to a simmer. Leave the soup to simmer for 10 minutes, and stir to ensure the miso is blended in with the broth.
- Arrange 4 oven proof bowls on a baking sheet and ladle the soup into each bowl. Top each bowl with a slice of bread and then sprinkle a layer of grated cheese overtop.
- Turn the oven on broil. Place the tray of soups in the oven and leave to broil for 2-3 minutes until the cheese has melted and is bubbly. Watch carefully to ensure that the cheese doesn’t burn.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Tried This Recipe?
Leave a comment below and let us know how it was!
Estimated reading time: 7 minutes
Wow this was good! Definitely the best french onion soup i’ve ever had.
My children loved this recipe. Thank you so much for sharing it!
If I don’t have a slow cooker with a sear/saute method, how would you recommend doing the first step?
I would saute the onions on the stove top and then transfer them to the slow cooker.
This is awesome, made it today!
So happy to hear that!
It looks really good but balsamic vinegar is SCD illegal. I will try to make it without the balsamic vinegar and thank you for this amazing site.
Thanks for the comment Dara! Balsamic Vinegar is actually allowed on the diet if it is high quality aged balsamic, the cheaper stuff with added sugar is not allowed