Butternut Squash Soup

from my Mom (via Sara Moulton Cooks at Home)

Ingredients

2 medium butternut squash or two packages of pre-cut squash (approx 6 cups)
2 Tablespoons unsalted butter
2 medium leeks, white parts only, thinly sliced
4 cups chicken stock, plus more as needed for thinning
Salt and freshly ground black pepper to taste

Instructions

Preheat the oven to 375 degrees.

If using whole squash, halve the squash lengthwise, scoop out the seeds (or scoop out after baking) and arrange cut side down on a foil-lined and lightly oiled baking sheet. If using pre-packaged squash, just place evenly on foil-lined and lightly oiled baking sheet. Bake until very tender, 50-60 minutes. Cool to room temperature. If using whole squash, when they are cool enough to handle, scrape out the pulp. You should have about 6 cups.

Heat the butter in a large soup pot over medium heat. Add the leeks and cook, stirring often, until softened, about 5 minutes. Add the squash and 4 cups of the chicken stock, increase the heat to high, and bring to a boil. Reduce the heat to medium-high and simmer, stirring often, until the leeks are tender, about 10 minutes. Puree the soup in the pot with an immersion blender until smooth. Thin with additional stock as needed (we like our soup thick!). Season with salt and pepper. Serves 4-6.