peel the squash and remove the seeds, then cut it into nice chunks.
You can make a soup by sauteeing some onion and garlic in a little olive oil, adding the squash and enough water or stock to cover it all, then simmer it gnetly until soft and blend the whole lot up.
Or you could add other vegetables as well, but I'd avoid potato as it will give it a grainy starchy texture.
Other spices and herbs can be added too, a bunch of fresh coriander and some cumin makes a nice spicy version, maybe with some chillie oil drizzled on top.
DS's favourite is butternut squash and red lentil, I literally just cook up the lentils with the squash and lots of water and a garlic clove and belnd the lot when cooked. Season with salt and pepper. Really simple and delish.
A little cream or creme freche is nice added once served too, for a creamy texture.