To a large saucepan add the olive oil and garlic & onion and cook over medium to high heat for 3-5 minutes until the onion and garlic soften.
Add all the remaining ingredients, bring to a boil, then reduce heat to medium, cover with a lid and cook for 25-30 minutes until the squash is soft.
Use a stick or immersion blender in the pot to blend, or allow to cool and transfer to a blender to blend till smooth.