Spread 4 slices of bread with the tapenade and top with the cheese. Sandwich with remaining bread and cut each sandwich into 3. Melt the butter in a large non-stick frying pan over medium heat. Place the eggs, milk, salt and pepper in a bowl and whisk to combine. Dip the sandwiches in the egg mixture and then press into the parmesan. Cook, in batches, for 1–2 minutes each side or until the bread is golden and the cheese is melted.