Step 1Preheat oven to 150°C.
Step 2Combine the garlic, anchovy, lemon juice, parsley, yoghurt and two-thirds of the parmesan in a large salad bowl. Place one-quarter of the mixture in a small bowl. Set aside.
Step 3Add coleslaw to the remaining yoghurt mixture, then toss to coat and set the salad aside.
Step 4Slice rolls and warm in oven for 5 minutes. Layer each roll with lettuce, tomato, chicken, onion, a little of the reserved yoghurt mixture and a sprinkle of parmesan. Put bun lid on top.
Step 5Serve burgers with coleslaw.