I drove up to Worcestershire yesterday to stay with my daughter Nicola for a couple of days. As Hurricane Ophelia gasped its last violent breath across Ireland, causing havoc and putting the whole country on Red Alert, the wind picked up during my drive up the M40, M42 and M5 and on into the smaller roads of Worcestershire on the eastern side of UK, near to Wales. Fortunately, Ophelia was pretty tame by the time she reached us but it was still a very windy night. This morning we woke to sun and while I love living in London, who can fail to be awed by the beauty of looking out onto some of UK’s prettiest land through an old farmhouse window and then going for a morning stroll up the lane.

I was cooking lunch. Just a simple soup I make quite often but this time in Nicola and Rachael’s Aga.

And that I discovered meant a totally different way of cooking: beginning as I usually do but then leaving the soup to cook in the simmering oven rather than bubbling away on top. I have to admit to be being slightly sceptical. I’ve roasted vegetables before for a soup, then when they’re cooked added liquid and blitzed till smooth, but I’ve never started with my basic ‘soffrito’ type mix and chopped vegetables, added liquid and then put it all in an oven to cook. It turned out to be a fantastic way of cooking for a gorgeous rich flavour and the fact that timing is very flexible. The soup can be happily left for some time and won’t spoil. And the Aga has a wonderful way of cooking the vegetables through without them collapsing if cooked for a long time. Nicola said this was especially great for cooking something like a vegetable curry where each vegetable will cook through but retain its separate integrity.

I do like to spice a winter soup up, so I added a little cumin, coriander seeds and dried chilli. I found some chillis in a jar and took them to Nicola to ask her how hot they were.

Nicola explained that Rachael had grown them then dried them herself and that they were VERY hot and I might only want about half with none of the seeds. So, although the chilli was small – only about 4cm – I did as suggested and it was as well I took advice, for the finished soup had a real chilli kick to it; we liked it but it was definitely enough. If you don’t want the soup hot or spicy, then leave the spices out; you’ll still have a lovely soup.

Carrot & Leek Soup with Spices

• 1 medium onion, chopped
• 3 large leeks (750g), thickly sliced
• 1kg carrots, thickly sliced
• dried chilli, cumin seeds, coriander seeds
• about 3 tablespoons extra virgin olive oil
• Salt & pepper
• vegetable stock or water

Prepare the vegetables. Grind some dried chilli with about a teaspoon each of cumin seeds and coriander seeds.

Put a large pan (with a tight fitting lid) on the simmering plate on top of the Aga. Add the olive oil and onion. Soften the onion a little and then add the spices. Stir and cook for a couple of minutes to bring out the flavour of the spices.

Now add the carrots and leeks and give a good stir. Season with salt and freshly ground black pepper. Allow to cook, stirring regularly, for 5 minutes or so until the vegetables take on a slight colour. Now add enough hot vegetable stock or water to just cover the vegetables.

Let it all come to just a simmer – a few bubbles at the edge – then put on the lid and transfer to the simmering oven of the Aga. This cooks it quite slowly – mine cooked for about 2 hours – but if you’re in more of a hurry, use a hotter oven. I’d prepared it all early so we had plenty of time to let it cook slowly. When ready, take from the oven and blitz until smooth with a hand blender.

It will be quite thick but I like this kind of winter soup thick. However, thin down to the consistency you want with some hot stock or water, if you like. We weren’t quite ready for lunch so I popped it back in the simmering oven where it could happily stay for some time without spoiling, until we were ready to eat.

I’d brought a sourdough loaf from my local Italian bakery yesterday and it was a perfect accompaniment.

The soup was delicious with such a good deep flavour. The slow cooking was brilliant. I topped it with a dollop of Greek yoghurt but some cream would be nice too. A perfect lunch in the wake of a dying hurricane on a windy, autumnal day.