Put the onion and carrots into a large saucepan with the stock, and bring to a boil.Reduce the heat and simmer, partially covered, for 20 to 25 minutes, or until the vegetables are tender.Blend the soup to a purée using a handheld stick blender – or transfer to a food processor or blender and whizz until smooth. Add most of the soft cheese and blend again until it is thoroughly mixed in.Reheat gently, then serve, garnished with the remaining cheese, a little black pepper and some scattered coriander (if using). Enjoy with a slice of wholemeal bread.