Preheat the oven to 180C degrees.
Peel the squash, remove the seeds and cut the flesh into bite sized chunks (measure out 450g exactly, if you’re counting the calories). Arrange them neatly in a baking dish.
Peel and finely slice the onion. Peel and roughly chop the garlic. Scatter these around the squash.
Pour over the stock, making sure the onion is covered by the the liquid.
Put the dish in the oven and bake for about 45 minutes, until the vegetables are soft and slightly brown. Transfer to a pan.
Dry-fry the curry powder until fragrant and browned. Add to the pan, together with the herbs.
Whiz the soup with a stick-blender until smooth.
Serve hot, garnished with some coriander leaves. You can add a dollop of natural yoghurt or crème fraiche of you like.