There is an old Italian proverb that the peasant should not be told how good cheese is with pear, and pecorino e pere is that proverb made into a sandwich. The pear is the defining half. Sweet, cold, faintly grainy, and wet, it is set against a firm, salty sheep's-milk cheese, and the panino works on the friction between the juicy fruit and the dense curd rather than on either by itself. The choice that matters is the pear: a crisp, slightly underripe one holds its shape and its bite in the bread, while a soft ripe one turns to paste and floods the crumb. The cheese is chosen to the fruit, firm enough to stand against the moisture, but it is the pear that the sandwich is named for and arranged around.
The craft is moisture management and keeping two textures distinct. The pear is sliced thin but not paper-thin, just before assembly so it does not brown or weep, and laid in single layers rather than piled, so it seasons the bite without soaking the bread. The pecorino is cut into firm slices that resist the fruit's water and give a salty, savoury floor under the sweetness. The bread is plain and sturdy, present to hold a wet element and stay structural, and almost nothing else goes in: a thread of honey or a few drops of oil at most, because the cheese-and-pear axis is already the complete idea and a third strong thing would only crowd it. It is built and eaten soon, while the pear is still crisp and cold against the room-temperature cheese.
The variations are about which cheese age and what bridges the two. There is the version with honey added to deepen the sweet side, the one using an aged sharper pecorino for more contrast, and the build that adds walnuts for a third texture. Each is the same fruit-and-cheese pairing with one element shifted, and each deserves its own article rather than being crowded in here.