If you love cozy, comforting soups that feel like a warm hug, you are going to adore this Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe. Silky, earthy celeriac joins forces with mild leeks and fragrant thyme, all blended into a luscious, velvety soup that’s perfectly balanced with a splash of cream. The crowning glory? Golden, melty Gruyère toasts that add the ultimate cheesy crunch. It’s a French-inspired classic that’s as indulgent as it is nourishing, making it an absolute favorite for chilly evenings or anytime you want to feel a little spoiled in your own kitchen.
Ingredients You’ll Need
Every ingredient in this Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe is carefully chosen to build layers of flavor and texture without overcomplicating things. Simple staples you likely have on hand combine to make something truly special, from the creamy root vegetables to the aromatic herbs and rich cheese. Here’s exactly what you’ll need:
- 2 tablespoons olive oil: Adds a fruity depth and helps gently cook the vegetables without browning.
- 2 tablespoons unsalted butter: Brings richness and a silky mouthfeel to the base of the soup.
- 2 leeks (white and light green parts), cleaned and sliced: Provide a subtle onion flavor with soft texture that’s key for the soup’s sweetness.
- 1 small onion, chopped: Adds an extra layer of aromatic complexity.
- 2 garlic cloves, minced: Gives a gentle punch of savory warmth and rounds out flavors.
- 1 medium celeriac (celery root), peeled and diced (about 1 ½ pounds): The star root vegetable with earthy, celery-like notes that create the soup’s unique character.
- 1 medium potato, peeled and diced: Contributes creaminess and helps thicken the soup naturally.
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried): Infuses the soup with its signature herbal aroma and subtle woodsy scent.
- 4 cups vegetable or chicken broth: The flavorful liquid base that ties everything together.
- 1 cup whole milk or cream: Adds luxurious smoothness and a mild sweetness.
- Salt and black pepper to taste: Essential for brightening and balancing the flavors.
- For the Gruyère Toasts:
- 1 small baguette, sliced: Crispy vehicle for the cheesy topping.
- 1 cup shredded Gruyère cheese: A perfectly nutty, meltable cheese with a golden crust when toasted.
- 1 teaspoon fresh thyme leaves: Echoes the thyme in the soup for harmony.
- Olive oil for brushing: Helps the bread brown beautifully under the broiler.
How to Make Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe
Step 1: Sauté the Aromatics
Begin by heating the olive oil and butter in a large pot over medium heat. Gently cook the sliced leeks, chopped onion, and minced garlic for about 5 to 7 minutes. The goal here is to soften the vegetables and coax out their natural sweetness without letting them brown, which will keep the soup’s flavor clean and mellow.
Step 2: Add Root Vegetables and Thyme
Once your aromatics are tender, toss in the diced celeriac and potato along with the fresh or dried thyme leaves. Stir everything so the veggies get coated with the buttery mixture and herbs. This is where the flavor foundation deepens, and you’ll already start smelling the inviting thyme mingling with those earthy roots.
Step 3: Simmer with Broth
Pour in the vegetable or chicken broth and bring the pot to a boil. Then, reduce the heat to low and let it simmer gently for 25 to 30 minutes. You’ll want the celeriac and potatoes to become completely tender, perfect for pureeing. The slow simmer helps all the flavors meld beautifully while softening the veggies to silky perfection.
Step 4: Puree the Soup
Once the vegetables are cooked through, remove the pot from heat and use an immersion blender to puree the soup until smooth. If you don’t have an immersion blender, carefully transfer the soup in batches to a blender. The goal is an ultra-creamy texture without lumps, which sets this soup apart as truly luxurious.
Step 5: Finish with Milk and Seasonings
Stir in the whole milk or cream, which makes the soup irresistibly smooth and sumptuous. Then season generously with salt and black pepper to your liking. Warm the soup over low heat just until heated through—avoid boiling once the milk is in to keep it silky and prevent curdling.
Step 6: Prepare the Gruyère Toasts
While the soup is finishing, preheat your broiler. Arrange the baguette slices on a baking sheet, brush each piece with olive oil, then sprinkle generously with shredded Gruyère and fresh thyme leaves. Place under the broiler for 1 to 2 minutes until the cheese melts and turns a beautiful golden brown. These toasts are the perfect crispy, savory partner for the smooth soup.
How to Serve Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe
Garnishes
Adding a bit of flair on top of your soup can transform the experience. Try a few fresh thyme sprigs or a small drizzle of high-quality olive oil for a glossy finish. A dusting of cracked black pepper or a few shavings of Gruyère right before serving feels indulgent and complements the toasts.
Side Dishes
This soup shines on its own, but if you want to create a heartier meal, consider serving alongside a crisp green salad dressed with a lemon vinaigrette or simple roasted vegetables. The freshness cuts through the creaminess and adds a welcome contrast in texture.
Creative Ways to Present
For entertaining, ladle the soup into small ramekins as appetizers and set the Gruyère toasts on a platter for a casual, shareable setup. Another fun twist is to float one or two Gruyère toasts directly in the bowls just before serving for a pretty presentation and extra cheesy bite with every spoonful.
Make Ahead and Storage
Storing Leftovers
This Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe stores beautifully in the fridge for up to three days. Transfer the soup to an airtight container and keep the toasted bread separate to maintain its crunch when reheated or served later.
Freezing
You can freeze the soup, but it’s best to do so before adding the milk or cream to preserve texture and flavor. Freeze in portion-sized containers for up to 2 months. When ready, thaw overnight in the fridge and add cream fresh when reheating.
Reheating
Reheat gently on the stovetop over low heat, stirring often to prevent the dairy from separating. You can also microwave in short bursts with stirring in between. Re-toast the Gruyère baguette slices fresh or warm them in a toaster oven for the best crispness.
FAQs
Can I use dried thyme instead of fresh?
Absolutely! You can substitute ½ teaspoon of dried thyme for 1 teaspoon of fresh. It still delivers that lovely herbal note, just add it during cooking to allow the flavors to bloom.
Is there a good dairy-free alternative for the cream and butter?
Yes, swap the butter for olive oil and use unsweetened plant-based milk, like oat or almond milk, instead of cream. The soup may be slightly less rich but will still be deliciously smooth and flavorful.
What if I can’t find celeriac? What’s a good substitute?
The closest substitute is celery root’s mild cousin, parsnip, which has a similar texture and sweetness. You could also try a mix of potato and fennel, though the flavor will be different but still wonderful.
Can I make this soup in advance for a dinner party?
Definitely. The soup tastes just as amazing reheated and can be made up to three days ahead. Prepare the Gruyère toasts fresh at serving time for the best texture and flavor.
How do I store the Gruyère toasts if not serving immediately?
Store them in an airtight container at room temperature if serving the same day, or reheat briefly under the broiler or in an oven toaster to refresh their perfect crispiness.
Final Thoughts
There is something truly special about the way this Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe comforts and delights all at once. It’s elegant enough to impress guests but humble enough to make any weeknight feel cozy and memorable. Next time you crave a warming bowl of soup, give this recipe a try—you’ll find yourself coming back to it season after season with a big, satisfied smile.
Print
Celeriac Leek Soup with Thyme & Gruyère Toasts Recipe
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Total Time: 45 minutes
- Yield: 4 servings
- Category: Soup
- Method: Stovetop
- Cuisine: French-Inspired
- Diet: Vegetarian
Description
This creamy Celeriac Leek Soup with Thyme & Gruyère Toasts is a comforting French-inspired dish perfect for chilly days. The silky pureed root vegetables flavored with fresh thyme create a rich, velvety soup, complemented beautifully by crispy baguette toasts topped with melted Gruyère cheese and thyme.
Ingredients
Soup
- 2 tablespoons olive oil
- 2 tablespoons unsalted butter
- 2 leeks (white and light green parts), cleaned and sliced
- 1 small onion, chopped
- 2 garlic cloves, minced
- 1 medium celeriac (celery root), peeled and diced (about 1 ½ pounds)
- 1 medium potato, peeled and diced
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried)
- 4 cups vegetable or chicken broth
- 1 cup whole milk or cream
- Salt and black pepper to taste
Gruyère Toasts
- 1 small baguette, sliced
- 1 cup shredded Gruyère cheese
- 1 teaspoon fresh thyme leaves
- Olive oil for brushing
Instructions
- Sauté Aromatics: Heat the olive oil and butter in a large pot over medium heat. Add the sliced leeks, chopped onion, and minced garlic. Cook for 5–7 minutes, stirring occasionally, until the vegetables are soft and fragrant but not browned.
- Add Vegetables and Thyme: Add the diced celeriac, potato, and fresh thyme leaves to the pot. Stir well to coat the vegetables with the aromatics and butter mixture.
- Simmer the Soup: Pour in the vegetable or chicken broth, bring the mixture to a boil, then reduce the heat to low. Let it simmer gently for 25–30 minutes, or until the celeriac and potato are very tender.
- Puree the Soup: Remove the pot from heat. Use an immersion blender to puree the soup until completely smooth. Alternatively, carefully transfer the soup in batches to a blender and blend until smooth. Return to the pot.
- Finish Soup: Stir in the whole milk or cream to add richness. Season with salt and black pepper to taste. Warm the soup gently over low heat until heated through, but do not boil.
- Prepare Gruyère Toasts: Preheat the broiler in your oven. Arrange the baguette slices on a baking sheet. Lightly brush each slice with olive oil, then sprinkle evenly with shredded Gruyère cheese and fresh thyme leaves.
- Broil Toasts: Place the baking sheet under the broiler for 1–2 minutes. Watch carefully and remove once the cheese is melted and golden brown.
- Serve: Ladle the hot soup into bowls and serve alongside the Gruyère toasts. Alternatively, float the toasts directly on top of the soup for an indulgent presentation.
Notes
- For a dairy-free version, substitute olive oil for butter and use unsweetened plant-based milk instead of whole milk or cream.
- The soup can be made ahead and refrigerated for up to 3 days; reheat gently before serving.
- You can use vegetable broth to keep the soup vegetarian or chicken broth for a slightly richer flavor.
- Fresh thyme is preferred for best flavor, but dried can be used in a pinch.
- For a smoother texture, strain the soup after blending if desired.
