Cut the cauliflower into 4-6 equal wedges ensure you keep a little of the stalk on to keep the wedges together.
Mix together the aci and tatli biber pastes with the olive oil and a little salt. Using gloves, rub the mix all over the cauliflower wedges making sure you get it right in the gaps between the florets.
Place the cauliflower on a cast iron tray or pan and pop into a hot Roccbox with the flame dial turned down slightly; you’re looking for a temperature of around 660°F.
Roast the cauliflower for 8-12 minutes turning with tongs occasionally. You want the paste to blacked and char on the cauliflower but don’t be afraid to turn the flame down if it’s a bit too fierce.
Check the cauliflower is cooked by piercing it in a few places with a skewer or small knife- there should be little resistance and the skewer should come out easily.
Whilst the cauliflower is roasting, combine the dressing ingredients in a bowl and season to taste.
To serve, transfer the roasted cauliflower to a platter, sprinkle with a little salt and sumac and top with the parsley and red onion and dress with the sumac dressing. Finally, sprinkle over the pistachios and serve.