Roasted sweetcorn soup with curry-spiced butter

Method

1. For the soup, preheat the oven to 220°C/fan200°C/gas 7. Lay the sweetcorn, side by side, in a small roasting tin and drizzle with a little (about 1 tbsp) of the melted butter. Season well, turn to coat and roast in the oven for 30 minutes, turning over halfway through, until the kernels are tender and lightly browned.
2. Remove the sweetcorn from the oven and leave to cool. One at a time, stand them upright on a plate or board and slice away the kernels from the cob with a large sharp knife, keeping the blade as close to the core as you can. Set aside.
3. Heat the rest of the melted butter in a medium pan. Add the onion, garlic, leek and carrot, cover and cook gently for 10 minutes. Meanwhile, make the curry butter. Heat a dry, heavy-based frying pan over a medium heat. Add the cumin and coriander seeds and shake them around for a few seconds until they have darkened slightly and smell nicely aromatic. Tip them into a spice grinder and grind to a fine powder. Put into a small bowl with the butter, chilli, turmeric, paprika, salt and some freshly ground pepper, then mix. Set aside somewhere cool, but don’t chill.
4. Add the stock to the vegetables and bring to the boil. Cover and simmer for 5 minutes until the vegetables are very soft. Add the roasted sweetcorn kernels and simmer a further 3 minutes. Leave the soup to cool, then purée (in batches if necessary) until smooth. Return to the pan and stir in the lemon juice, sugar and some salt and pepper to taste. Reheat the soup gently until piping hot, then ladle into warmed bowls, swirl a heaped teaspoonful of the curry butter into each one and serve immediately.