1 cup aioli
1 tsp sumac
Zest and juice of ½ lemon
8 flathead fillets
Sea-salt flakes and freshly ground black pepper, to season
100ml extra virgin olive oil
1 loaf Turkish bread
¼ iceberg lettuce, leaves separated
1 small red onion, finely diced
¼ bunch coriander, leaves picked, to serve
Extra sumac, to serve
Lemon wedges, to serve
Put aioli, sumac, lemon zest and juice in a small bowl and stir to combine. Cover and put in fridge.
Preheat barbecue hotplate or a large frying pan over a medium-high heat. Preheat barbecue grill or a grill pan over a medium-high heat.
Put fish on a large plate and season. Brush with ½ of the oil. Cook for 2 minutes on each side.
Meanwhile, cut loaf into 4 hamburger bun-sized pieces and split each in half horizontally. Brush cut side of each piece with remaining oil. Grill on both sides until lightly toasted.
To assemble, divide lettuce among 4 pieces of toasted bread. Top with fish and a large dollop of aioli mixture, then scatter over onion. Scatter over coriander leaves and a sprinkle over extra sumac. Sandwich with remaining bread and serve with lemon wedges.