Autumn is the perfect time to start serving up soups again. This makes a great lunch, but if the family have had a substantial lunch it can also make a comforting supper served up with lots of fresh crusty bread. Sweet potatoes are full of goodness and flavour and the coconut milk adds a luxurious creamy base to this soup. You can make it up to 2-3 days in advance and keep it covered in the fridge. You can freeze it for up to a month, but blitz it with a hand blender upon defrosting as it may split.
• 450g sweet potatoes, cut into cubes
• 2 tbsp sunflower oil
• 1 onion, finely chopped
• 1 leek, trimmed and finely chopped
• 1 lemongrass stalk, trimmed and halved
• 1 red chilli, halved, seeded and thinly sliced
• 1 tsp freshly grated root ginger
• 1.25l of vegetable or chicken stock
• 4 tsp tomato puree
• 400g tin of coconut milk
• Sea salt and freshly ground black pepper
• Chilli oil to garnish (optional)
1. Preheat the oven to 200ºC. Place the sweet potatoes on a baking sheet, drizzle over 1 tbsp of the sunflower oil and roast for 20-30 minutes until tender. Set aside.
2. Heat the remaining oil in a pan over medium heat. Add the onion, leek, lemongrass, half the chilli and ginger and sweat for 4 minutes, stirring occasionally. Add the roasted sweet potato with the stock and tomato puree, then bring to the boil. Reduce the heat and simmer for 10 minutes until the liquid has slightly reduced and all the vegetables are tender.
3. Pour the coconut milk into the pan, reserving about 3 tablespoons from the top of the tin as a garnish, and cook for another 5 minutes, stirring constantly. Season to taste. Remove the lemongrass stalk and blend with a hand blender until smooth.
4. To serve, ladle the soup into warmed bowls and swirl in the reserved coconut milk. Add a drizzle of chilli oil and sprinkle the reserved chilli slices over the top.