Add the dried chillis to a bowl and soak in boiling water.
Remove the outer leaves and as much stalk as you can without cutting any of the florets off.
Add the cauliflower upside down into boiling water and boil for 15 minutes, flipping over in the water for the last 5 minutes. (It should be nearly cooked through).
Drain the water and leave to dry.
Remove the seeds from the chillis and add to a high speed blender cup with the rest of the harissa ingredients.
Blend the sauce until completely smooth.
Brush the harissa generously on the cauliflower top and bottom making sure to get into all of the cracks.
Save some of the harissa for basting.
Air fry on 180C for 10 minutes.
Brush on some more harissa.
Air fry on 180C for another 10 minutes and baste again.
Air fry for a further 5-10 minutes and test that the cauliflower is cooked by putting a knife through to the core. It should be easy to push the knife through.
Serve with more harissa and fresh parsley to garnish.