Cut the carrot, onion and celery into a 5mm (¼") dice.
Slice the garlic as thinly as you can.
Heat half of the butter over a medium heat in a 20cm or 8" saucepan.
Add the onion, garlic, carrot and celeriac and cook for 10 minutes.
Cut the cauliflower into 1-2cm (½-¾") florets, finely slicing any stalks.
Add the cumin to the onion mix cook for a further 1 minute.
Add the cauliflower and stir to combine, then pour in the vegetable stock and add the bay leaf, and allow to cook for 10 minutes.
Heat the remaining butter over a medium heat in a 15cm or 6" saucepan.
When melted add in the flour and cook out the flour for 5 minutes stirring continuously.
Add 50ml (3 tablespoons) of the milk to this mix and beat until it is thoroughly combined. Repeat this process until all of the milk has been combined and you have a thick and smooth sauce.
Add this sauce to the soup mix and cook for a further 5 minutes
Remove from the heat and stir in the chopped parsley.