For the smokey barbecue sauce; combine all the ingredients in a non-stick saucepan. Bring to a simmer over medium heat, stirring often. Simmer for 5 minutes. Remove from the heat.

Preheat oven 230°C. Grease two large baking trays. Remove the outer leaves from each cauliflower, leaving the core intact. Cut two, 2.5cm-thick steaks from the centre of each cauliflower, reserve the rest of the florets for another use like cauliflower cheese or roast cauliflower salad.

Put the cauliflower steaks onto two trays. Brush both sides of cauliflower steaks with smokey barbecue sauce. Season with salt and pepper. Roast for 30 minutes, swapping trays around in the oven after 20 minutes or until the cauliflower is tender and charring at the edges.

Brush with a little more sauce, top with mayonnaise and parsley, serve with salad.