Remove the skin and the seeds from the butternut, and cut into cubes.
Place the cubed butternut in a saucepan with water.
Cover, with a lid, bring to a boil, then reduce to a simmer for 10 minutes until the butternut is tender.
Drain, reserving the liquid.
Blend your butternut (with spices) if you are using it until a smooth texture is achieved, add liquid as needed to reach a velvety smooth consistency. You can use either a blender or a food processor for this step. If you are making this for your baby stop at this step.
If you are adding butter add cubed butter to the smooth puree and blend until it is well mixed.
Taste and salt as needed for a family meal.