Photograph: Martin Poole
Heat the oil in a medium pan and fry the onions over a medium heat until soft, 8-10 minutes. Meanwhile, roughly chop half the sprouts and cut the rest into halves or quarters, depending on size.
Add the garlic to the pan and stir-fry for 1 minute, then add the chopped sprouts and stock, cover with a lid and bring to the boil. Take the pan off the heat and leave to cool slightly.
Purée the soup. Stir the cream, remaining sprouts, cheese and some seasoning into the pan and simmer for 2-3 minutes or until the cheese has melted. Serve with a drizzle of olive oil and a scattering of extra cheese.
Kitchen secret: if you love sprouts so much you don't have any leftovers, simply cook raw sprouts in boiling salted water for 8-10 minutes, or until tender.