Heat the oil in a large pot over medium-high heat. Add the onion and allow to brown.
Reduce heat to medium-low. Add beet, rutabaga, cauliflower and sweet potato cubes. Sweat for 5-6 minutes.
Add the vegetable stock and bring to the boil. When the stock comes to the boil, reduce the heat and add the remaining ingredients, except for the creamy soy mixture. Simmer for about 20 minutes.
Remove from heat, allow to cool, then use a blender to purée until smooth.
Add the creamy soy mixture and stir lightly to blend well.