Peel the butternut squash and weigh the required amount of skinless, uncooked squash.
Chop into smaller pieces.
Add to a steamer and steam for 15-20minutes until it is soft.
Mash up the squash or blend in a blender to make it smooth. You now have butternut squash puree.
If you do not have a steamer - bring water to the boil in large saucepan and sit a sieve or colander on top of the saucepan so that the bottom does not touch water. Add the squash to the sieve or colander and then put the pan lid over the top. The squash will steam.