In a large salad bowl or mixing bowl, add the yoghurt, parmesan, lemon juice, mustard, garlic, anchovy fillet (if using) and a generous grind of black pepper. Whisk until thoroughly combined.
To the same bowl, add the Brussels sprouts, shallot, hazelnuts, cranberries and parsley. Toss until thoroughly combined and coated in the dressing. Serve.
