Discard the green leaves of the cauliflower then tear it into small florets. Peel the parsnip and chop into chunks. Set them aside.
In a small frying pan, dry-toast the ground spices for a couple of minutes until fragrant. Set aside.
Heat the oil in a large saucepan over a medium heat and fry the onion for 8 minutes until soft. Add the garlic and cook for 2 minutes. Add the toasted spices and the bay leaves and stir for a minute. Add the cauliflower and parsnip, then pour in the stock. Bring to the boil, then gently simmer for 25-30 minutes until the vegetables are tender.
Remove and discard the bay leaves, then whizz the soup using a stick blender until you get a smooth, velvety soup. Season to taste.
Serve warm.