250g/9oz Brussels sprouts, trimmed, outer leaves peeled and a deep cross cut in the base of each sprout
truffle mayonnaise, for dipping (optional)
175g/6oz plain flour
salt and freshly ground black pepper
1 tbsp cornflour
3 tbsp olive oil
1 tbsp truffle oil, plus extra for drizzling
vegetable oil, for deep-frying
3 free-range egg whites
3 tbsp grated Parmesan
truffle salt and crumbled truffle pecorino, for sprinkling