Celeriac With Hazelnut Crumble

There's something about autumn that makes me crave pale, earthy soups that taste like they came straight from a root cellar. One crisp October afternoon, my neighbor handed me a knobby celeriac from her garden and asked if I knew what to do with it. I didn't, not really, but I roasted it anyway, and the kitchen filled with this nutty, almost sweet aroma that made me stop what I was doing. That's when the idea struck: blend it into something silky, then top it with something crunchy to keep things interesting.

I made this for my partner on a rainy Thursday when everything felt a little too hectic, and watching them close their eyes after the first spoonful reminded me why I love cooking. The combination of that velvety soup with the crunch of toasted hazelnuts somehow felt like the whole point of eating together, you know?

Ingredients

• Celeriac: The star of the show, this gnarly root vegetable has a subtle celery-parsnip flavor that becomes almost buttery when roasted, and at about 700 grams you'll have plenty for a silky base.
• Onion and garlic: Standard aromatics that build the flavor foundation, nothing fancy but everything depends on them being soft and fragrant.
• Potato: This keeps the soup naturally creamy without needing excessive cream, and it helps bind everything into that silky texture you're after.
• Vegetable broth: Use something with real depth, not the super salty stuff, because you're tasting it in every spoonful.
• Olive oil: About 2 tablespoons total, split between roasting and sautéing to build layers of flavor.
• Heavy cream or plant-based alternative: Optional but recommended, it rounds out the earthiness and adds elegance without being heavy.
• Sea salt and black pepper: Freshly ground pepper makes a real difference here, trust me on this.
• Ground nutmeg: Just a quarter teaspoon, but it's the whisper that ties everything together and makes people ask what that subtle warmth is.
• Hazelnuts: Whole ones that you'll roughly chop and toast until they smell like a forest, about 60 grams gives you enough crunch without overwhelming the delicate soup.
• Unsalted butter: For toasting the hazelnuts, though olive oil works if you're keeping it vegan and honestly tastes just as good.
• Fresh parsley: A tablespoon finely chopped, stirred in at the last second so it stays bright and green against the pale soup.

Instructions

Roast the celeriac until it turns golden:

Preheat your oven to 200°C, toss your diced celeriac with a tablespoon of olive oil on a baking sheet, and let it spend 25 to 30 minutes in the heat, stirring once halfway through. You want the edges to caramelize slightly and the inside to be completely tender.

Build your aromatic base:

In a large pot over medium heat, warm a tablespoon of olive oil and sauté your diced onion and minced garlic for 3 to 4 minutes until they're soft and starting to turn translucent. This is where the foundational flavor comes from, so don't rush it.

Combine everything and simmer:

Add your roasted celeriac and diced potato to the pot, pour in 900 milliliters of vegetable broth, and bring it to a boil before dropping the heat down to a gentle simmer. Let it bubble away for 15 to 20 minutes until the vegetables are completely soft and falling apart.

Toast the hazelnuts while the soup cooks:

In a small skillet over medium heat, melt your butter and add roughly chopped hazelnuts, toasting for 2 to 3 minutes until they're golden and smell absolutely incredible. Stir in your finely chopped parsley and a pinch of salt, then set aside.

Blend until completely smooth:

Using an immersion blender, puree the soup right in the pot until there are no lumps and it looks like silk, or carefully transfer it in batches to a stand blender if that's what you have. This is therapeutic, actually.

Season and finish:

Stir in your cream if using, that quarter teaspoon of nutmeg, and taste carefully as you add salt and pepper until it makes you happy. Reheat gently if needed, but don't let it boil once the cream is in.

Serve with intention:

Ladle the soup into bowls and crown each one generously with your hazelnut crumble, watching as the crunchy bits float on top and slowly soften into the warmth below.

Save to Pinterest

My sister came over unexpectedly one evening, and I had this soup on the stove, and she ended up staying for two bowls and we talked about everything and nothing for hours. That's when I realized this soup isn't just comfort food, it's an excuse to slow down.

The Art of Roasting Root Vegetables

Roasting vegetables before you soup them is like the difference between telling a story and living it. The dry heat of the oven concentrates sugars and creates that subtle browning that boiling simply cannot achieve. I learned this by accident when I was too lazy to chop the celeriac into soup-sized pieces and just threw whole ones in the oven instead, and yes, they took forever, but the flavor was so deep I've been roasting ever since.

Why Cream Is Optional But Worth Considering

I made this soup both ways to see if it really mattered, and honestly, without cream it's still beautiful and earthy and completely satisfying. With cream, though, it becomes something that feels like you're treating yourself, like this is soup for a Friday night or when you want to feel a little fancy. The potato does most of the work making it velvety anyway, the cream just adds a whisper of elegance that rounds out the earthiness and makes it feel more like a dinner party than just dinner.

The Hazelnut Crumble Changes Everything

This isn't just a topping, it's the reason this soup stays interesting to the very last spoonful. Texture is everything, and without it, you're eating something that's just one note, even if that note is beautiful. The contrast between the silky soup and the crunchy, toasted hazelnuts is where the magic lives, and once you taste it you'll understand why I obsess over making sure those nuts are golden and fragrant.

• Toast your hazelnuts until they smell like a forest floor in the best way, that nutty warmth is your signal they're ready.
• Chop them roughly so you get different sizes, some pieces disappear into the soup while others stay crunchy.
• Make the crumble right before you serve if you can, because there's nothing sad about hazelnut crumble that's sat around getting soft.

Save to Pinterest

This soup has become my go-to when I want to feel like I'm taking care of people, including myself. Make it once and you'll be making it again, probably for someone you want to impress.

Recipe FAQs

→ What does celeriac taste like?

Celeriac offers a mild, sweet flavor with subtle celery notes and earthy undertones. When roasted, its natural sugars caramelize beautifully, creating depth that pairs perfectly with the rich, buttery hazelnut topping.

→ Can I make this soup ahead of time?

Absolutely. Prepare the soup base up to three days in advance and refrigerate. Store the hazelnut crumble separately in an airtight container. Reheat gently on the stove, adding a splash of broth if needed, and sprinkle with fresh crumble just before serving.

→ What can I substitute for hazelnuts?

Toasted pecans or walnuts work beautifully as alternatives, offering similar richness and crunch. For nut-free options, try pumpkin seeds or sunflower seeds—they'll still provide that essential textural contrast against the silky soup.

→ How do I achieve the smoothest texture?

Roasting the celeriac first softens the fibers, making it easier to blend completely smooth. Use an immersion blender for several minutes, or pass the soup through a fine-mesh sieve after blending for restaurant-quality silkiness.

→ Is the cream necessary?

The cream adds luxurious body, but the soup remains delicious without it. The potato naturally thickens the broth, creating satisfying creaminess. For dairy-free versions, coconut cream or cashew cream provides similar richness while keeping the dish plant-based.

→ What wines pair well with this soup?

Crisp white wines like Sauvignon Blanc, Pinot Grigio, or dry Riesling complement the earthy celeriac beautifully. The wine's acidity cuts through the creaminess while highlighting the hazelnuts' buttery notes. For red wine lovers, a light Pinot Noir works nicely.