This soup serves 4 and costs around 0.96p to make (pricing the ingredients from a supermarket). I often look out for a head of celery when my local supermarket reduces them. I find celery keeps well in the fridge, up to a week after the sell by date, so even if you don’t have the time to make it straight away, it’ll keep until you do.
1 chopped onion
1 tbsp olive oil
1 head of celery
1 vegetable stock cube
Freshly ground black pepper
Gently fry the onion in the oil until it is translucent and soft, keeping the lid on the saucepan. Meanwhile slice the bottom off the head of celery (and the top leaves if it has any – these can be washed and kept to decorate your soup). Wash the celery and slice it across the stems in fairly small strips. Add the celery to the onion and stir well, replace lid and cook on a low heat for 10 mins. Add the stock cube, crumbled and stir in 1 litre of water*. Replace lid and simmer gently for 25 mins. Allow to cool a little, season with a couple of twists of black pepper and then liquidise and serve.
*If you have used the frugal chicken recipes here and have the chicken stock ready, you can use that instead of a stock cube and water.
For a special occasion you can add a swirl of cream (not so frugal!) and a celery leaf to garnish. This soup freezes well if you don’t need the whole quantity.