Prepare the marinade: In a bowl, combine lemon juice, extra virgin olive oil, salt, and pepper. Whisk well to mix.
Marinate the salmon: Place the thinly sliced salmon into the marinade and mix well to coat all slices. Refrigerate for 1 hour to allow flavors to develop.
Prepare the avocado: Slice the ripe avocado thinly. To prevent browning, sprinkle a few drops of lemon juice over the slices.
Make the creamy filling: In a bowl, mix Philadelphia cream cheese with lime zest, a drizzle of olive oil, salt, and pepper. Stir until smooth and creamy.
Heat the piadine: Warm each piadina for about 1 minute on each side until heated through.
Assemble the rolls: On each warmed piadina, layer marinated salmon slices, avocado slices, tomato slices, and finally the creamy cheese mixture. Roll the piadina first one way, then the other to form a roll.
Serve: Plate the piadina rolls and serve immediately as a fresh and flavorful aperitif.