Celeriac, for me, is January produce royalty, and there's no use for it more classic than soup. Its fragrant, slightly sweet flavour works perfectly with hazelnuts, so using hazelnut milk is a naturally delicious vegan swap for the dairy you'd find in your traditional "creamy soup."
With some toasted hazelnuts on top, and a bit of hot chilli oil, this soup a great winter warmer.
I highly recommend making your own stock here. To do so, just add a celeriac, a few stalks of celery, half an onion, and a few handfuls of fresh herbs if you have them lying around (sage, tarragon, and thyme are great), all roughly diced, to a large pot of water with a bit of salt. Boil for at least an hour, then strain. If you don't have the time or inclination to make stock, shop-bought is fine (or even just water).
Fresh hazelnut milk is also the best option here; it will yield the most hazelnutty flavour. To make this, just soak about 200g hazelnuts in 1l water overnight. Blend and strain the next day. Shop-bought hazelnut milk will also do the job; if you want to use this and try and up the nut flavour, you could stir in a little hazelnut butter along with your milk (although I've not tried this myself).
Celeriac and Hazelnut Soup
Preparation time: c. 50 minutes
2 tbsp garlic oil
1 medium-large celeriac, peeled and diced
5 medium-large potatoes, peeled and diced
750ml good-quality vegetable stock (see above)
750ml hazelnut milk (see above)
1 tsp English mustard
A squeeze of lemon juice
Ground sea salt
1./ Heat the garlic oil in a large saucepan or pot. Add to this the diced celeriac and potatoes and fry over a medium-high heat for about 5 minutes, till they're just about starting to soften and brown.
2./ In the meantime, in a separate pan, combine the stock and hazelnut milk and bring almost to the boil.
3./ Add the hot milk/ stock mixture to the frying celeriac and potatoes. Stir in a bit more salt (unless your stock is particularly salty) and leave over medium-high heat for a good 20 minutes. Turn down the heat to low and keep simmering for a further 10 minutes. By this stage there should be a fair bit of liquid left over, and the vegetables should be nicely softened.
4./ Blend everything until smooth. For a super-silky finish, pass the soup through a sieve.
5./ Serve with crusty sourdough, toasted hazelnuts, and chilli oil.
Until next time...