To make puree: slice a butternut squash in half, remove the seeds, and place cut side down in a roasting pan. Fill with a 1/4" of water and roast butternut squash at 425˚ until tender, 40-50 minutes depending on size. Remove and scoop out the squash. Alternatively, peel and cube butternut squash. Bring a pot of water to a boil and add butternut squash. Boil until tender and mash.