Melt the butter in a saucepan, then add the harissa, lemon zest, lemon juice and garlic, and cook for 2-3 mins, until sizzling. Season with pepper and stir in most of the parsley, reserving a little to garnish.

Wash and discard any damaged or blemished outer leaves of the cabbage. Cut in half, keeping the root intact, then cut each half into 2 wedges, keeping the root attached to each end. Carefully thread onto metal skewers, brush each wedge with the harissa butter, then set aside on a baking tray.

Brush the neutral oil over the bars of the barbecue and grill the cabbage, brushing with the butter occasionally, turning carefully every 3-5 mins, until soft and charred all over. Alternatively, you can cook these under a hot grill.

Spread the yogurt out on a serving platter and top with the skewers, drizzling over any remaining butter, then scatter with the crispy onions and reserved parsley.