When it comes to comfort food, few dishes rival a steaming bowl of French onion soup.
Now imagine that same classic elevated with a delicate smoky note. This is Woodfire Smoked Onion Soup: a savory, layered version of French onion soup where cold-smoking adds depth to both the onions and the cheese.
This Page Contains Affiliate Links. For more Info See My Disclosures.
Woodfire Smoked Onion Soup takes caramelized onions, rich beef broth and a golden cheesy crust and enhances them with a mild smoke. Using a smoker like the Ninja Woodfire Grill, you can cold-smoke the onions and cheeses to add aroma without cooking them, then finish the soup in a pot and brown the cheese under high heat for an unforgettable bowl.
Why Cold-Smoke Ingredients?
Cold-smoking infuses flavor without applying heat, so the onions keep their natural sweetness and the cheeses pick up a subtle, savory smoke. That contrast — sweet caramelized onion against smoky, melted cheese — is what makes this twist so compelling.
What Makes This Version Stand Out?
Several key choices lift this soup above the ordinary:
- Cold-smoked onions and cheese for a gentle smoky aroma that complements the caramelization.
- Gruyère plus Gouda—Gruyère brings classic nutty notes while Gouda melts into a creamy, slightly smoky topping.
- Using the Ninja Woodfire or a similar smoker to cold-smoke delicate ingredients and then broil the finished bowls for a beautifully browned top.
Overview of the Method
Start by cold-smoking whole onions and blocks of cheese until they pick up the desired level of smoke. Thinly slice the smoked onions, then slowly caramelize them in butter and oil with thyme and bay leaves. Add a bit of flour, deglaze with cooking wine, then pour in beef broth and simmer. Ladle the soup into oven-safe bowls, top with toasted buttered baguette slices and a generous mix of smoked Gruyère and Gouda, then broil until the cheese is bubbling and browned.
Tips for Success
- Caramelize slowly: Cook onions over low to medium-low heat for at least 45 minutes to extract their full sweetness.
- Slice evenly: Use a mandolin or a very sharp knife to slice onions thinly so they caramelize uniformly.
- Balance your cheeses: A roughly equal mix of Gruyère and Gouda gives nutty flavor and creamy melt without overpowering the soup.
- Watch the broil: When finishing the bowls under high heat, keep a close eye so the cheese browns without burning. Use heat-resistant gloves to handle hot bowls.
Verdict
If you enjoy traditional French onion soup, this smoked variation is worth the extra step. The smoky layer adds complexity while preserving everything you love about the original: sweet onions, rich broth and a crunchy, cheesy crust. It’s a great dish for entertaining or for treating yourself to an elevated comfort meal.
Recipe
Woodfire Smoked Onion Soup
Equipment
- Ninja Woodfire Grill or another smoker
- Cutting board and knife
- Mandolin (optional)
- High-heat gloves
- Ninja elevated rack or air crisp basket
- Large pot or Dutch oven
- Stove or burner
- Measuring cups and spoons
- Large spoon and ladle
- Oven-safe soup bowls and a cheese grater
Ingredients
- 6 large sweet onions
- 3/4 cup Gruyère, shredded
- 3/4 cup Gouda, shredded
- 6 cups beef broth
- 6 tbsp butter, divided
- 2 tbsp olive oil
- 2 tbsp flour
- 1/2 cup cooking wine (sherry or dry white)
- 1 tbsp sea salt
- 1 tbsp black pepper
- 1 tsp thyme
- 2 bay leaves
- 1 baguette, sliced
Instructions
Optional: Cold-smoke the cheese & onions
- Set your smoker to the cold-smoke setting (if available). Place whole onions and blocks of cheese on the elevated rack or in the air fry basket. Smoke for 45 minutes to 2 hours depending on desired smokiness. Grate 3/4 cup of each cheese and set aside.
- Trim the onion tops and bottoms and peel them. Thinly slice to about 1/8″ (a mandolin makes this easy).
Make the soup
- In a large pot or Dutch oven over low heat, add 4 tbsp butter and the olive oil. When the butter melts, add the sliced onions, salt, pepper, thyme and bay leaves. Raise heat to medium-low and cook, stirring occasionally, until the onions are deeply caramelized (about 45 minutes). Remove bay leaves.
- Add the flour and stir to combine. Increase heat to medium-high and deglaze with the cooking wine, scraping up browned bits. Simmer 2–3 minutes.
- Add the beef broth, bring to a boil, then reduce heat and simmer for 30–45 minutes to meld flavors.
Assemble and finish
- Preheat your smoker or oven to the broil setting.
- Slice the baguette into 1/2″ pieces, butter with the remaining butter, and toast briefly under broil until golden.
- Ladle soup into oven-safe bowls, place a toasted baguette slice on top, then cover generously with the Gruyère/Gouda mixture, making sure cheese overlaps the bowl edges.
- Place bowls directly on the grate (not on the rack or basket) and broil 1–2 minutes until the cheese bubbles and browns. Use heat-resistant gloves when handling hot bowls.
Cool and serve
- Let the bowls cool a few minutes, then enjoy.
Nutrition
Tried this recipe?
Notes
If you don’t have a cold-smoke option, you can skip the smoking step and still make an excellent French onion soup. Cold-smoking is an optional enhancement that adds a gentle smoky character.
About the Author
Dad shares recipes and cooking videos focused on approachable techniques and flavorful results. The Woodfire Smoked Onion Soup is one of those recipes that rewards a little patience with big flavor.