Perfect Butternut Squash Soup

2 large butternut squash or 4 lbs peeled and cubed butternut squash

2 medium onions, chopped

3 cloves garlic

1 T freshly grated ginger

1 t ground ginger

3 T butter or oil

1/2 t salt 

8 c chicken or vegetable broth

Halve, seed, peel, and cube the butternut squash.  Set aside. Heat a large pot over medium-high heat.  Add butter or oil and the onion.  Sprinkle with 1/2 t salt.  cook stirring occasionally, until the onion is soft, about 3 minutes.  Add the garlic and ginger 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 very tender, about 20 minutes. Transfer small batches to a blender.  Blend until completely smooth, 2-3 minutes per batch.  Return the soup to the pot and add more salt to taste.