Method
1. Toss potatoes with 2 tblsps of the oil in a large roasting pan. Season with salt and pepper.
2. Cook in a hot oven (200C), turning halfway through, for about 35 minutes, or until golden brown and tender.
3. Meanwhile, to make the dressing, blend all the ingredients in a blender until smooth. Season.
4. Cut fish into 3cm pieces. Place in a large bowl with remaining oil and 1 tblsp dressing. Season with salt and pepper. Thread onto skewers.
5. Heat an oiled, large grill plate over a medium heat. Add skewers in 2 batches. Cook, turning occasionally, for about 6 minutes, or until cooked through. Remove.
6. Serve skewers drizzled with remaining dressing, potatoes and lemon. Garnish with basil.