Slice the onion into rings and throw it in a big pan with the olive oil.
Cook on a low-medium for 3 minutes. Chop the garlic roughly and cook for another minute.
In the meantime, roughly chop the broccoli and cauliflower.
Make the veggie stock as per packet instructions.
Throw the broccoli and cauliflower into the pan.
Add the stock and simmer for fifteen minutes.
Turn the heat off and add the cheddar cheese. Hold just a little cheddar cheese back for serving. Add the thyme, basil and mustard. Give it all a good stir and let the flavours mix together for a few minutes.
Finally, use a hand blender and give it a blend!
Serve with fresh bread and a few herbs of choice for garnish.