Peel and quarter the butternut squash. Scoop out the seeds and cut into chunks.
Heat the oil in a large, heavy based pan with a lid and cook the onion until translucent.
Stir in the curry paste before adding the butternut squash, celery and lentils. Stir well to coat the vegetables and lentils.
Add the stock, cover and simmer for 15-20 minutes until the lentils are tender and the squash has softened. Take off the heat.
Stir in the coconut milk, ginger, coriander and lime juice and zest.
Blitz in your blender until smooth and reheat if necessary.