I found this in the Nov 2011 issue of Bon Appétit, they strained the ginger and used heavy cream. I lightened it up by using 1/2 and 1/2 and lots of ginger. I also reheated it in the oven.
2 kabocha squash, halved, seeded
Salt and pepper
1 6″ piece of ginger, peeled, thinly sliced
1 tablespoon light brown sugar
3/4 c half and half
Preheat oven to 375°F. Line a rimmed baking sheet with parchment or foil. Season inside of squash with salt and pepper. Place squash, cut side down, on prepared sheet. Roast until tender, 1-1 1/4 hours. Let cool slightly.
Pulse ginger in a food processor until finely chopped. Scoop squash flesh into a food processor. Add sugar, with machine running, gradually add 1/2 & 1/2 and purée until smooth, adding more cream by tablespoonfuls if too thick. Season with salt, pepper.