In a large pot melt the butter over medium heat. Add the chopped onion and cook for 2 to 3 minutes, stirring occasionally, until softened and translucent.
Add the cubed butternut squash, minced garlic, and ginger. Stir and cook for 1 minute until the garlic is fragrant.
Pour in the low sodium chicken broth and bring to a boil over high heat. Once boiling reduce the heat to a steady simmer and cook uncovered for 10 minutes until the squash is completely tender and easily pierced with a fork.
Remove from heat. Using an immersion blender blend the soup directly in the pot until completely smooth and creamy with no chunks remaining. If you do not have an immersion blender carefully transfer the soup in batches to a regular blender, hold the lid down with a folded towel, and blend until smooth then return to the pot.
Return the pot to medium high heat and cook for an additional 7 to 10 minutes, stirring occasionally, until the soup has thickened slightly and reached your desired consistency.
Season with salt and black pepper, taste and adjust as needed, then ladle into bowls and serve hot.