It was a chance, last-minute decision to make this gorgeous soup today. I popped into Waitrose to buy a few things, saw a wonderful knobbly celeriac and couldn’t resist buying it. With the cold mornings and evenings we’ve had over the last week or so, and days drawing in, it’s soup time again. I love to have some portions of homemade soup in my freezer ready for a quick lunch on an autumn or winter’s day.

Despite its rather ugly appearance – for which it’s known and, I guess, puts some people off – celeriac is a beautiful and versatile vegetable and, despite its bland cream flesh, surprisingly good for you. It has lots of health benefits including being a good source of calcium and magnesium, so is good for bone health. It also has good amount of potassium, so is good for regulating blood pressure, and is a great source of Vitamin C and other minerals and vitamins. As the name suggests, it’s related to celery and has a similar flavour but is nuttier in taste with a lovely creamy texture when cooked. It’s been used in European cooking since the 1600s and some say it was first cultivated in Italy. But it goes back as far as the 8th century when it was mentioned in Homer’s The Odyssey as selinon.

To be honest, it’s not why I like it. I like the ‘bonus’ of the health benefits but I buy it and eat it because I love the taste. It wonderful raw in the famous French salad, Remoulade de Celeri-Rave, and I like it as a mash – half and half with potato – to go with a rich winter stew. I’ve made it as a simple soup before, but while I was having a light lunch and watching the end of an old Hairy Bikers’ programme about apples and pears on iPlayer, their soup made with celeriac and apples came up and the coincidence was too great to resist.

And, of course, it’s the apple season with lovely British apples coming into the shops. Some Cox’s apples I had were just crying out to be paired with the knobbly celeriac.

I followed the Hairy Bikers’ recipe pretty much to the letter, with just slight adjustments. They garnish the soup at the end with crispy bacon, which sounds lovely, but I was going for the vegetarian option today and was also planning to freeze much of it.

Celeriac & Apple Soup

• 3 eating apples
• 50g butter
• 1 tablespoon extra virgin olive oil
• 2 medium (125g) onions, chopped
• 1 celeriac (about 800g), peeled and cut into chunks
• 1 large carrot, cut into chunks
• 2 garlic cloves, crushed
• 1 large (250g) potato, peeled and cut into chunks
• 1 level teaspoon dried oregano or thyme
• 1 litre stock
• sea salt and freshly ground black pepper

Peel the apples, core and cut into quarters. Melt 25g butter in a pan and add the apple. Fry over a medium heat until lightly browned and caramelised.

Meanwhile, in another large saucepan, melt the remaining butter with the olive oil. Tip in the prepared onions, celeriac and carrot. Gently cook for about 15 minutes until softening and starting to brown. Then add the apples (with their juices), garlic and potato. Sprinkle over the dried herbs (the Hairy Bikers used fresh thyme and a bay leaf – to be removed before blitzing at end) and cook for just a few minutes, stirring to mix well.

Pour in the stock – use whatever you prefer, vegetable or a light chicken stock. Season with salt and pepper. Bring to a boil and turn down to simmer for about 25 minutes, or until the vegetables are soft. Stir occasionally. When cooked, blitz the soup with a stick blender until smooth.

I served it with a dollop of natural yoghurt and some chopped fresh parsley, and drizzled a little extra virgin olive oil over it. You might prefer crème fraîche or even fresh cream if you’re feeling indulgent.

It was such a gorgeous soup and a wonderful marriage of the nutty celeriac with the sweet caramelised apples. A perfect dish for a cold autumn day.