This French onion chicken soup combines sweet caramelized onions, tender chicken, and a savory thyme-infused broth with gluten-free toast and melted Gruyère. It’s a hearty dinner with the flavors of French onion soup, plus a dairy-free option.
There’s something about caramelized onions and bubbling cheese toast that makes a bowl of soup feel like a complete comfort-food dinner. This version adds chicken thighs for a satisfying meal, while keeping the broth rich and savory without cream.
The onions take a little patience, but the ingredients are simple. Once they’re deeply golden, the chicken finishes cooking right in the broth. Add the cheesy toast just before serving so you get crisp edges, melted cheese, and a little broth-soaked bread in every bowl.
Why You’ll Love This French Onion Chicken Soup
- Caramelized onion flavor: Slowly cooking the onions builds sweetness and depth without added sugar.
- Tender chicken: Boneless chicken thighs turn an onion soup into a hearty main dish.
- Gluten-free cheese toast: Use your favorite sturdy gluten-free bread for the golden topping.
- Flexible servings: The soup base is dairy-free, so you can add cheese toast to individual bowls.
- Make-ahead friendly: Prepare the soup ahead and make the toast when you’re ready to eat.
Ingredients and Substitutions
Yellow onions: These are the foundation of the soup. Three pounds looks like a lot at first, but the onions shrink considerably as they cook. Slice them evenly so they soften and brown at a similar rate.
Boneless, skinless chicken thighs: Thighs stay tender during simmering and are easy to shred into bite-size pieces. Trim excess fat before browning.
Olive oil: Used for the chicken, onions, and toast. It keeps the soup base dairy-free.
Beef broth: Low-sodium beef broth gives the soup a deeper, more traditional French onion flavor. You can use half beef broth and half chicken broth for a lighter result. Check that your broth is gluten-free.
Dry white wine: Helps loosen the flavorful browned bits from the pot. For a version without wine, substitute an equal amount of broth.
Garlic, thyme, and bay leaf: These complement the onions without overwhelming them. Fresh or dried thyme works.
Balsamic vinegar: A small amount at the end balances the sweetness of the onions. Start with one teaspoon, then taste before adding more.
Gluten-free bread: Choose sturdy slices that will hold the cheese. Toast them on both sides before adding them to the soup.
Gruyère: Adds a nutty, savory finish. Grate it fresh for the topping. Swiss cheese is an alternative if you don’t have Gruyère.
See the recipe card below for the complete ingredient list and measurements.
How to Make French Onion Chicken Soup
Brown the chicken
Season the chicken and brown it in olive oil in a large Dutch oven. You’re building flavor here; the chicken will finish cooking in the broth. Transfer it to a plate while you cook the onions.
Caramelize the onions
Add the remaining oil, sliced onions, and salt. Cook until the onions soften and collapse, then reduce the heat and continue cooking until they are deeply golden.
Stir every few minutes, more frequently as they brown. If the bottom of the pot gets too dark, add a small splash of water and scrape up the browned bits. The onions should become soft and golden throughout, without blackened edges.
Add the broth and simmer
Stir in the garlic and thyme, then add the wine and scrape the bottom of the pot. Pour in the broth, add the bay leaf, and return the chicken with its juices.
Simmer gently until the chicken is cooked through and tender. Shred it into bite-size pieces and return it to the soup. Finish with the balsamic vinegar and adjust the seasoning.
Make the Gruyère toasts
Brush the bread lightly with olive oil and toast it on both sides. Add the cheese and broil until melted and lightly golden, then place a toast on each bowl of hot soup.
You can also add the toasted bread and cheese directly to filled broiler-safe bowls and broil them on a sturdy baking sheet. Either way, serve immediately.
Tips for the Best Flavor and Texture
Let the onions set the pace. Depending on your pot, heat, and the moisture in the onions, caramelization can take longer than expected. Look for deep golden color and a soft, jammy texture before adding the broth.
Use a wide, heavy pot. A wide Dutch oven helps moisture evaporate and gives the onions more contact with the cooking surface.
Taste before adding more salt. Broth varies in saltiness, and the cheese adds another savory layer.
Keep the soup at a gentle simmer. Once the chicken goes in, avoid a vigorous boil.
Toast the bread thoroughly. Crisping both sides helps it hold up when it meets the broth. Add the topping only when you’re ready to serve.
Dairy-Free and Paleo Options
The soup base uses olive oil and contains no cream, butter, or cheese.
For a dairy-free serving, leave off the Gruyère and serve with dairy-free gluten-free toast if desired. For a paleo version, omit the conventional gluten-free bread and cheese and use broth that fits your needs.
You can also try my sandwich bread, dinner rolls or biscuits if you want a paleo friendly bread option!
The version pictured includes dairy cheese and gluten-free bread; it is not paleo.
Frequently Asked Questions
Can I use chicken broth instead of beef broth?
Yes. Chicken broth gives the soup a lighter flavor. Beef broth creates a deeper, more traditional French onion profile, and a combination of the two works as well.
Can I make it without wine?
Yes. Replace the wine with the same amount of broth, using it to scrape up the browned bits. Taste the finished soup before deciding whether it needs a little more balsamic vinegar.
Do I need flour to thicken the soup?
No. This is a brothy soup with plenty of onions and chicken. It does not need flour, starch, or cream.
Do I need special bowls?
Only if you plan to broil the assembled bowls. For ordinary serving bowls, melt the cheese on the toasted bread on a baking sheet, then transfer the toasts to the soup.
Make Ahead, Storage, and Reheating
Store the soup separately from the bread and cheese topping. Refrigerate promptly in shallow airtight containers and use within 3–4 days.
Reheat the soup in a saucepan until hot throughout, adding a splash of broth if needed. Prepare fresh cheese toasts just before serving.
For longer storage, freeze the soup without the toppings for up to 3 months for best quality. Thaw in the refrigerator before reheating.
What to Serve With French Onion Chicken Soup
With chicken and cheese toast, this soup makes a substantial dinner on its own! Pair it with a simple green salad with a tangy vinaigrette or roasted vegetables.
More Paleo Soup Recipes You’ll Love
Tuscan Chicken Butternut Squash Soup
Butternut Squash Chicken Chili
Chicken Pot Pie Soup with Low Carb Biscuits
French Onion Chicken Soup Recipe
Ingredients
Soup:
- 3 tablespoons olive oil divided
- 1½ pounds boneless skinless chicken thighs, excess fat trimmed
- 1 teaspoon fine sea salt divided, plus more to taste
- ½ teaspoon freshly ground black pepper plus more to taste
- 3 pounds yellow onions weighed before peeling, peeled, halved, and sliced approximately ⅛ inch thick
- 4 garlic cloves minced
- 2 teaspoons fresh thyme leaves or ¾ teaspoon dried thyme
- ½ cup dry white wine or additional broth
- 5 cups gluten-free beef broth plus up to 1 additional cup as needed
- 1 bay leaf
- 1 teaspoon balsamic vinegar plus more to taste
Gruyère toasts:
- 6 slices sturdy gluten-free bread sized or trimmed to fit the bowls*
- Olive oil for lightly brushing the bread
- 6 ounces Gruyère cheese freshly grated
- Fresh thyme leaves and black pepper for serving
Instructions
-
Brown the chicken: Pat the chicken dry and season with ½ teaspoon salt and the black pepper. Heat 1 tablespoon olive oil in a large, heavy Dutch oven over medium-high heat. Brown the chicken for approximately 3 minutes per side, working in batches if necessary. Transfer to a plate; it will finish cooking in the soup.
-
Soften the onions: Reduce the heat to medium and add the remaining 2 tablespoons olive oil, sliced onions, and remaining ½ teaspoon salt. Cook for 10–15 minutes, stirring frequently, until softened and beginning to collapse. If the browned bits on the bottom threaten to burn, add a small splash of water and scrape them up.
-
Caramelize: Reduce the heat to medium-low and continue cooking for approximately 30–45 minutes longer, until the onions are deeply golden and very soft. Stir every few minutes, more frequently toward the end. Add water 1–2 tablespoons at a time if the bottom gets too dark. Allow extra time if needed; use the color and texture as your guide.
-
Deglaze: Stir in the garlic and thyme and cook for 1 minute. Pour in the wine or additional broth and scrape up the browned bits. Simmer for 2–3 minutes.
-
Simmer: Add 5 cups broth, the bay leaf, and the chicken with its accumulated juices. Bring to a gentle boil, then reduce the heat and simmer partially covered for 18–25 minutes, until the chicken is tender and reaches at least 165°F in the thickest part.
-
Finish the soup: Transfer the chicken to a clean plate and shred into bite-size pieces. Return it to the pot and discard the bay leaf. Stir in the balsamic vinegar. Taste and adjust the salt and pepper. Add up to 1 additional cup broth if desired and a little more vinegar only if needed.
-
Toast the bread: While the soup simmers, preheat the oven to 425°F. Lightly brush both sides of the bread with olive oil and place on a rimmed baking sheet. Bake for 8–12 minutes, flipping halfway through, until crisp on both sides. Check early, as gluten-free breads vary.
-
Melt the cheese: Switch the oven to broil. Divide the grated Gruyère evenly among the toasts. Broil on the baking sheet for approximately 1–3 minutes, watching continuously, until the cheese is melted and lightly golden.
-
Serve: Ladle the hot soup into bowls and add a cheese toast to each serving. Finish with fresh thyme and black pepper and serve immediately.
Recipe Notes
- Broiling in bowls: Instead of melting the cheese on the baking sheet, place broiler-safe bowls on a sturdy rimmed baking sheet. Fill with hot soup, leaving room for the topping. Add the toasted bread and cheese, then broil until melted and golden. Handle the hot bowls carefully.
- Broth: Use all beef broth or a combination of beef and chicken broth. Check labels to keep the recipe gluten-free.
- Dairy-free: Omit the cheese and use dairy-free bread if serving toast.
- Paleo: Omit the conventional gluten-free bread and cheese and choose suitable broth.
- Without wine: Substitute ½ cup additional broth for the wine.
- Timing: Caramelization varies with the pot, stove, and onions. Allow extra time if the onions are still pale.
- Storage: Refrigerate soup without toppings for 3–4 days. Prepare fresh toasts when serving.
Leave a Comment