Mary Berry Celeriac & Watercress Soup Recipe

I’ll be honest—celeriac used to intimidate me. It looks like a knobbly turnip with a bad attitude. But once you peel past the rough exterior, it turns into the silkiest soup base you could imagine.

The first time I tried this, I overcooked the watercress and the soup turned a sad khaki colour instead of vibrant green. It still tasted fine, but it looked like army rations. The second time, I added the watercress right at the end, and voilà—bright, fresh, and full of life.

If you’re after something that feels fancy but is secretly easy, this is the soup. Let me show you how to keep it lush and lovely.

WHY THIS ONE WORKS SO WELL

• Celeriac is naturally creamy – No need for lots of cream.
• Watercress adds peppery zing – But only if you don’t overcook it.
• Blends like a dream – Especially if you’ve got a hand blender on standby.

INGREDIENTS + WHY THEY MATTER

• Sunflower oil (2 tbsp) – Neutral flavour, great for sautéing the onions.
• Onions (2 large) – Gives a sweet base to balance the earthy celeriac.
• Celeriac (750g) – When cooked, it turns velvety and light—like a healthier potato.
• Vegetable or chicken stock (1.5 litres) – Either works. Chicken gives a richer flavour, veg keeps it light.
• Watercress (200g) – Adds colour and a peppery bite. Only cook it briefly!
• Crème fraîche or double cream (about 4 tbsp) – Optional, but adds a beautiful richness.
• Salt and pepper – Don’t skimp here. The right seasoning makes all the difference.

MAKING IT YOURS (WITHOUT RUINING IT)

• Dairy-free? Skip the cream and swirl in a bit of oat milk or cashew cream at the end.
• Want more bite? Add a handful of spinach with the watercress to deepen the green.
• No celeriac? Parsnips or turnips give a similar vibe, though not quite as silky.

MISTAKES I’VE MADE (AND HOW TO AVOID THEM)

WHAT WENT WRONG	WHY IT HAPPENS	HOW TO FIX IT
Soup turned dull green	Overcooked the watercress	Add right at the end—2–3 mins only
Soup too thin	Added too much stock early	Start with less, thin it at the end
Chunky texture	Didn’t blend long enough	Use a stick blender for a smooth finish

HOW TO MAKE MARY BERRY’S CELERIAC & WATERCRESS SOUP

COOK THE ONIONS
Heat 2 tbsp sunflower oil in a deep saucepan. Add 2 chopped onions and fry for about 5 minutes, until starting to brown.

ADD CELERIAC
Add 750g diced celeriac and fry for another 4–5 minutes, letting it pick up a bit of colour.

POUR IN STOCK
Add 1.5 litres vegetable or chicken stock. Season well. Bring to the boil, then reduce heat, cover, and simmer for 15–20 minutes until the celeriac is tender.

ADD WATERCRESS
Stir in 200g watercress and cook for just 2–3 minutes until wilted.

BLEND + FINISH
Use a hand blender to blitz until smooth. Stir in 4 tbsp crème fraîche or double cream. Taste and season again if needed.

SERVE
Ladle into warm bowls and garnish with a few reserved sprigs of watercress. Perfect with a warm muffin or crusty bread.

TIPS FROM MY KITCHEN

• I use chicken stock for depth, but veg stock makes it feel lighter.
• Always add the cream off the heat—it can split if you boil it.
• If you’re freezing this, do it before adding the cream. Stir that in when reheating.

STORAGE + SERVING

• Fridge: Keeps for 3 days in a sealed container.
• Freezer: Freeze without the cream for up to 3 months. Defrost and reheat gently.
• Reheat: On the hob over low heat, stirring until piping hot.

FREQUENTLY ASKED QUESTIONS

Q: Can I use watercress from a bag?
A: Yes, just check it’s fresh and not soggy. Even slightly wilted leaves work fine once blended.

Q: Can I skip the cream?
A: Absolutely. It’s still creamy thanks to the celeriac. But the crème fraîche does give it a nice tang.

Q: Is this soup vegetarian?
A: It is if you use vegetable stock. Check your stock cubes or liquid for hidden meat products.

Try More Recipes:

• Mary Berry 10 Minute Tomato Soup​
• Mary Berry Smoked Haddock Soup
• Mary Berry Pea and Mint Soup Recipe