Mozzarella in Carrozza

Preparation

1. In a bowl whisk together the egg and the milk and transfer the mixture to a shallow bowl. Put the bread crumbs in another shallow bowl. Spread the bread slices with 1 1/2 teaspoons of the anchovy paste, put 1 slice of the mozzarella on each of 4 bread slices and top the mozzarella with the remaining bread slices, forming sandwiches. Working with 1 sandwich at a time, dip the sandwiches into the egg mixture, letting the excess drip off, and coat them with the bread crumbs. In a large heavy skillet heat the oil and the butter over moderately high heat until the fat is hot but not smoking and in the fat sauté the sandwiches, turning them and gently flattening them with a spatula, for 6 minutes, or until the mozzarella is melted and the bread is golden. Divide the sandwiches between 2 heated plates and keep them warm. To the skillet add the lemon juice, the tomato, the green peppercorns, the remaining 1/4 teaspoon anchovy paste, and salt and black pepper to taste and cook the mixture over high heat, whisking, until it is heated through. Spoon the sauce over the sandwiches and sprinkle the sandwiches with the parsley.