1 (2-3 Pound) winter squash (blue hubbard, butternut, or red kuri), halved lengthwise and seeded
2 tablespoons butter
1 medium onion, chopped
6 cups vegetable stock
6 fresh sage leaves, minced
Salt and freshly ground black pepper
Heat oven to 425°F and arrange a rack in the middle. Line a baking sheet with aluminum foil.
Place the squash pieces cut-side up on the baking sheet. Melt 1 tablespoon of the butter and brush all of it over the tops and insides of the squash halves (alternatively, you can rub it on evenly with your fingers).
Season generously with salt and pepper. Roast until knife tender, about 50 minutes to 1 hour.
When the squash is ready, set the baking sheet on a wire rack until the squash is cool enough to handle.
Using a large spoon, scoop the flesh into a bowl, set aside.
In large pot melt butter. Add onion and sage and cook until translucent, about 8 minutes.
Add squash and stock. Reduce the heat to medium low and simmer, stirring occasionally and breaking up any large pieces of squash, until the flavors meld, about 15 minutes.