Press the mozzarella slices between paper towels for 15 minutes to pull out excess water. Pat dry again before assembling.

Lay 4 bread slices flat and top each with mozzarella. Scatter chopped anchovy and parsley over the cheese if using, then top with the remaining bread slices.

Press the edges firmly with your fingers to seal, then run a rolling pin over the border of each sandwich to flatten and lock the seal.

Set up two shallow bowls, one with flour, one with the eggs whisked together with milk, salt, and pepper.

Dredge each sandwich in flour on both sides, tapping off the excess, then dip fully into the egg mixture, letting extra drip back into the bowl.

Heat the oil in a 25 cm / 10-inch skillet over medium heat to 170 C / 340 F. Test with a thermometer or drop in a bread cube, it should sizzle and turn golden in about 20 seconds.

Fry the sandwiches 2 at a time so the oil temperature stays steady, 3 to 4 minutes per side, until the crust is deep golden and the edges look sealed and puffed.

Lift out with tongs and drain on a wire rack set over a sheet pan. Repeat with the remaining sandwiches, checking the oil returns to 170 C / 340 F between batches.

Cut each sandwich in half while hot and serve right away, while the cheese still pulls when you tear it apart.