I found this in the Spice & Spirit of Kosher Passover Cooking cookbook. It isn't really much of a recipe at all -- which is how things usually are on Pesach if, like my family, the basic extent of available seasonings is salt! I'm sure additional spices would enhance this, but it's pretty good just as written. I had a pretty huge squash, so I used 8 cups of water, which was probably too much... I'm submitting the recipe as it's written in the cookbook, but feel free to play with the amounts!
- Cook butternut squash in water until soft, about 15 minutes. Let cool to room temperature.
- Transfer to food processor and puree until desired consistency is reached. (If you have a lot of water left over, I wouldn't recommend pouring it all into the food processor -- it makes quite a mess!) Add salt to taste.