This is a fantastic soup for the autumn.

• Start by frying a chopped onion.
• Blitz together a thumb sized piece of root ginger, two cloves of garlic and a chilli (decide what strength suits your pallet) before adding to the frying onion.
• Add two teaspoons of cumin seeds, a teaspoon of ground coriander, two teaspoons of ground turmeric and a teaspoon of fennel seeds to the pan and lower the heat whilst stirring in the spices.
• Add about 600g of washed and diced parsnips to the pan and stir for a few minutes before adding enough stock to just cover the parsnips.
• Turn the heat up and cover the pan whilst you leave the parsnips to cook. When the parsnips are tender turn off the heat and add a chopped eating apple minus the core to the pan before blitzing up using a food processor until smooth. Season with salt to taste.

• Peel and thickly slice the sweet potatoes. Heat the oil in a large saucepan over a medium heat, add the onion and fry gently for a few minutes until softened and glossy, stirring occasionally, then add the garlic, cumin and chilli and fry for a minute longer.
• Add the sweet potato and continue to cook for another couple of minutes, stirring frequently. Pour in the stock and season with salt, bring to the boil and simmer over a low heat for 20 minutes, by which time the sweet potato should be meltingly tender.
• Liquidise the soup in batches. Return it to the pan and season with a little more salt if necessary.
• Combine the feta and yoghurt in a bowl and serve spooned on top of the soup, scattered with a teaspoon of chopped sun-dried tomato if wished.