Heat the oil in a large saucepan and add the onion and thyme. Cook gently for 5 minutes until the onion is softened.
Stir in the cauliflower florets and toss well with the onion. Cook for just a minute. Stir in the stock, bring to the boil and simmer for 10 minutes until the cauliflower is very tender.
Pour in the milk and simmer for a further 2-3 minutes, then add the nutmeg and Cheddar cheese and remove from the heat.
Using a blender, blitz until smooth and creamy.
Preheat the grill. To serve, place the bread cubes in a baking tray and add the oil, cayenne (for adults) and parmesan cheese – toss together well. Place under the grill and toast, tossing well every few minutes until golden and crunchy. Serve sprinkled on top of the soup.
Cook's tip: for babies, serve the soup with lightly buttered fingers of bread. For toddlers, serve with plain croutons.