Roasted Butternut Squash Soup

1 large or 2 medium butternut squash (about 4 1/2 pounds), or 3 pounds peeled and cubed2 medium onions (can use leeks as well)3 cloves garlic, optional3 tablespoons unsalted butter, or vegetable oil1/2 teaspoon fine sea salt, plus more to taste8 cups chicken or vegetable brothChives and Pepitas for garnish, if desired 

Halve, seed, peel, and cube the butternut squash. Set aside.

Halve, peel, and chop onion. Mince the garlic, if you're using it.

Heat a large pot over medium-high heat. Add the butter or oil and the chopped onion. Sprinkle with 1/2 teaspoon salt. Cook, stirring occasionally, until the onion is soft, about 3 minutes.

Add the garlic and cook until fragrant, about 1 minute.

Add the squash and the broth. Bring to a boil. Cover, reduce heat to a simmer, and cook until the squash is tender, about 20 minutes.

Transfer small batches to a blender. Hold a kitchen towel over the top (to prevent burns) and whirl until completely and utterly smooth, 2 to 3 minutes per batch.

Return the soup to the pot and add more salt to taste. Garnish as desired.