Celeriac, Caramelised Shallot and Brown Butter Soup
Celeriac, or celery root, is one of my favourite root vegetables. It’s sweet and refreshing enough to be eaten raw and even sweeter and luxurious when cooked. The heart and soul of this dish is the soup itself, it creates a delicious foundation to the dish supported by a few additional garnishes. These are important because they offer textural contrast and pockets of flavour which make the soup more interesting and delicious.
The flavour of the soup predominitaley comes from the sweetness and mild earthiness of the celeriac but is complemented by even more sweetness and some depth from the caramelised shallots and is finished by pureeing in plenty of brown butter. This makes it luxuriously smooth and gives it a comforting, familiar flavour. A little bit of lemon juice to finish does well to balance out the sweetness and richness.
For the Puree
1 large (roughly 1kg) celeriac, peeled
6 (roughly 350g) shallots, peeled
4 cloves (30g) garlic, peeled and
3 Stalks (150g) celery, sliced
4 sprigs thyme
200g brown butter
For the Celeriac Crumble
200g celeriac, peeled
1lt of neutral oil
Salt to taste
For the Sauteed Celeriac
400g celeriac, peeled
2 Sprigs of thyme
1 clove of garlic
Olive oil and salt to taste
Picked celery, parsley and tarragon leaves
For the soup
1. Remove the knobbly root end off the bottom of the celeriac and cut a flat edge on the opposite side. Lay the celeriac flat onto the chopping board and peel around the outside using a knife.You can use a peeler but the skin will often be too thick for most peelers. Once peeled, cut into quarters and cut each of those quarters into thin slices.
2. Plate a pot large enough to hold 4 litres onto the stove and add some olive oil or brown butter. Add the sliced shallots to the pan along with a few sprigs of thyme. You can tie the thyme branches together with a piece of string to make them easier to remove from the soup later. Season with a pinch of salt and cook over medium heat for 10 minutes while stirring occasionally.
3. Once the shallots have taken on a golden hue, add the sliced garlic and the sliced celery and continue to cook while stirring for 3 minutes or so to take the raw edge off of the garlic.
4. Add the sliced celeriac to the pot and stir to coat with the other vegetables. Season liberally with salt. Turn the heat up to high and add 1.5 litres of water, chicken or vegetable stock.
Water will give you a cleaner flavour while chicken stock will give you the richest soup.
5. Bring up to the boil and cook with the lid on for 10 minutes. Remove the lid and stir. Continue to cook for 15 more minutes or until the celeriac is so tender enough that it can be crushed with the back of a spoon.
6. To finish either insert an immersion blender into the pot or carefully add the contents of your pot in batches into a blender. Add the brown butter, a squeeze of lemon juice and blend on high. Adjust the seasoning with salt and the consistency with more stock or water. Blend for a few minutes until the soup is a silky smooth puree. For an extra luxurious finish, pass the soup through a fine meshed strainer.
For Sauteed Celeriac
7. Cut the celeriac into small cubes, roughly 1cm wide. Quickly saute over medium high heat with 2 tablespoons of brown butter or olive oil, 2 sprigs of thyme and a pinch of salt. Stir constantly until they are browned nicely. Remove from the pan and lay them out onto some paper towels to absorb excess fat.
8. Alternatively cut the cubes slightly larger, season well with olive oil and salt and place onto a lined baking tray and into an oven set to 180C. Roast for 20 minutes or until the celeriac is cooked through and browned.
For the Celeriac Crumble
9. This is a delightfully crunchy celeriac crumble topping that you can use to add texture to a number of other recipes. It’s a little bit of extra work but it’s a great technique to know and something I’ve used with a number of root vegetables like potato or jerusalem artichoke to great effect.
10. Roughly chop your celeriac and place into the bowl of a blender with 1 litre of water and 20g of salt. Blend on medium-low until the celeriac resembles coarse pebbles and sand.
11. Strain the contents of the blender through a sieve and rinse off the celeriac to remove any excess starch.
12. Place the celeriac shards onto a kitchen towel and wring out as much moisture as you can.
13. Place a pot onto the stove that can hold at least 2 litres of liquid. Place 1 litre of cooking oil in the pan and add half of the celeriac. Turn the temperature on the stove up to high.
14. Check the temperature of the pot while stirring it occasionally until the heat reaches 110C. Keep the temperature at 110C to remove as much moisture as possible from the celeriac, continue to stir. Once the celeriac stops bubbling it should slowly start to brown. Once browned, remove and allow to dry out on some paper towel to absorb excess oil and season with salt. .
15. Once cooled to room temperature, reserve in an airtight container for up to 2 days or 7 if stored with a silica gel packet.
Yeah, the little sachets you find in newly bought boxes of shoes actually have other uses. These little desiccant packets absorb moisture from their surroundings and are great for storing certain dry goods. Preferably buy these purposely for food purposes rather than literally taking them from the insides of your last shoebox!
To add some visual and textural interest to the dish we’ve included the two other preparations of celeriac in the form of the crumble and the sauteed pieces. The soup itself has a creamy, mild flavour from the celeriac while the crumb and the sauteed pieces will offer some more texture and depth to the dish.
The pomegranate here offers some additional sweetness and a crunchy, acidic counterbalance to the richness of the soup. I went for pomegranate because it happened to be in season at the time of writing. Some roast or poached apple or pear pieces would be a great alternative that pairs perfectly with celeriac.
The celery I used for the soup has plenty of little leaves on the inside. The little yellow ones especially have a nice light celery flavour. This coupled with the grassiness of parsley and the anise punch of tarragon made for a beautiful pairing with the soup. Having said that, plenty of herbs would be a great fi:. Chives, sage, chervil – there are plenty of options here.
Having eaten this soup a few times since I originally wrote this article, I have been enjoying the addition of capers to add little briney pops that complement the flavours perfectly as well as small pieces of cheese folded into the hot soup. Personal favourites being oozey little chunks of taleggio,aged cheddar and grated parmesan.
A nice way of serving this dish is to have the garnishes in the bowl sit off to one side, nicely arranged and the hot soup to be poured over at the last minute. This is a nice touch if you’re trying to impress your dinner guest or want to make an impression. When the occasion calls for less formality I am a big fan of heating up a quick bowl of this in a pot or microwave and folding in the sauteed celeriac and any cheese and then just coating the top with the celeriac crumble, plenty of herbs and pomegranate.
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