1) Cut down the center of the pumpkin so that you have two halves.
2) Scoop out the seeds and the pulp. Cut each half into 4-5 vertical slices. Sprinkle with salt.
3) Cook for about 50 minutes at 350 degrees F until soft. Let it cool.
4) Remove the skin and scrape the soft pumpkin into a bowl. Use a food processor or a masher until the pumpkin is a relatively smooth and homogenous mixture. If your mixture seems dry, add a little water to moisten the purée.
5) Freeze for up to 3 months or refrigerate for up to a week.