Make the butter. Combine all the ingredients in a stand mixer and mix using the paddle attachment. In the absence of a mixer, whisk in a large bowl until thoroughly incorporated. The butter should be aerated, slightly stiff and one colour (as opposed to streaked). Set aside until needed. It can be kept in the fridge for several weeks, but must be brought to room temperature before being used.
Trim some of the outer cauliflower leaves, but leave some stragglers left behind – they taste delicious and look great when burnt and crisped. Set a large saucepan of salted water on high heat and cover with a lid so as to bring the water up to the boil. Once the water is boiling, gently lower the cauliflower into the pan, being careful not to let it drop from a height and thereby avoiding the potential of burning yourself with the splash-back of boiling water. Bring the water back to the boil, then turn the heat down to medium so the water has a gentle roll. The intention is to par-cook the cauliflower before finishing it in the oven or on the barbecue. It should be removed from the water when tender to a knife, yet retain some resistance – ‘al dente’, as they say. We’ve found it to take seven minutes from when the water comes back to the boil.
Set the cauliflower on a cooling rack over a roasting tray and allow to drip-dry. Brush liberally all over with the spiced butter, and where possible, try and get beneath the floret canopy to reach the inner sections. Retain some of the butter for brushing at a later stage. Season generously with salt and pepper.
Preheat the oven to its highest setting (240°C/220°C Fan/Gas mark 9) and blast the cauliflower for five to seven minutes, until blackened all over. (You want it to lightly char, not to form an acrid burnt crust.) Once sufficiently oven-roasted, transfer it to finish on the barbecue for a few minutes (if you have one going) for a final hit of smokiness, basting it periodically with any leftover butter.
Transfer to a serving plate. Spoon over the tahina sauce and pomegranate molasses, and finish by sprinkling over the pine nuts, green chilli, pomegranate seeds, rose petals and parsley. A drizzle of olive oil adds a nice glossy finish. Serve immediately – the cauliflower tastes so much better when hot.