Place the olive oil in a dutch oven or sauce pan over medium heat on the stovetop. Once the oil is hot, add the onion and butternut squash cubes (just the flesh, remove the skin). Cook for 10 minutes until butternut squash is fork-tender.
Add all remaining ingredients and stir well to combine. Increase heat to medium high and bring to a boil. Reduce heat to medium low and simmer for about 35-45 minutes until everything is very tender.
Remove dutch oven or pot from heat and use an immersion blender inside pot to puree ingredients together until smooth. Allow to cool to room temperature, then carefully transfer to a blender and puree until smooth with the lid or kitchen towel on top. Enjoy