Melt the butter with the oil in a large saucepan and stir in the onion, garlic, carrots, celery and sweet potato. Cook over a medium heat for 10 minutes, stirring regularly until the vegetables are beginning to soften and brown lightly. Stir in the apple pieces and sprinkle over the curry powder. Cook for a further 2 minutes more, stirring as it cooks.

Crumble the stock cube into a measuring jug, and pour over the boiling water. Mix to combine. Pour into the pan, and stir in the tomato purée and mango chutney. Bring to the boil, then reduce the heat slightly and leave to simmer for 30 minutes, stirring occasionally . Cook until the vegetables are tender.

While the soup is simmering, half-fill a medium pan with water and bring to the boil. Add the rice and return to the boil. Cook for 10 minutes, or until the rice is tender. Drain the rice in a sieve and rinse under running water until cold.

When the soup is ready, cool the soup for a few minutes and blend with a stick blender or in a food processor until smooth before stirring in the cooled rice. If you want a more rustic texture to the soup, do not blend.

Add enough water to give a good consistency, (about 150-200ml/5½-7fl oz). Heat the soup for 3–4 minutes until piping hot and check the seasoning, add salt and freshly ground black pepper to taste.

Ladle the soup into deep bowls and top each with a spoonful of natural yoghurt or soured cream. Garnish with sprigs of coriander or flat-leaf parsley if you like.