1. Peel and remove the seeds from the butternut squash.
2. Peel the carrots and red onion and then chop all the vegetables into small chunks.
3. In a large saucepan heat the oil and add all the vegetables and seasoning.
4. Gently sweat the vegetables over a medium heat with the lid on for 15 minutes, stirring occasionally.
5. Meanwhile, boil the water and prepare the stock by dissolving the cube into it.
6. Add the stock to the pan, bring to the boil and simmer for 10 minutes.
7. Remove from the heat and, using a blender (hand or jug), blend the soup until smooth.
8. Pour into a bowl and enjoy.