Heat oven to 175ºC and roast the butternut until soft but not brown. I love how this adds to the flavour.  Alternatively you can just steam the butternut until soft.

Heat a saucepan over medium high heat and add oil and onion, and saute for 3 minutes.

Add curry paste , garlic, and ginger and saute for a minute or two, stirring constantly.

Add the roasted butternut and the stock and cover and bring to the boil.

Reduce the heat, and add the coconut milk and salt to taste.  Simmer for 5 minutes stirring frequently.

Blend everything until smooth using  an immersion blender, or in a food processor.

As a delicious addition serve with a side bowl of roasted peanuts to add to the soup, and lime wedges for a fresh squeeze of added zing.