In a bowl, mix tuna, lemon aioli, olive oil, lemon juice, capers, dijon mustard, and salt and pepper, until well blended. Cut Pane Turano bread into 4 slices. Divide the tuna mixture evenly across the bread, add arugula and top with remaining slice of bread. Place in a skillet over medium heat, cook on both sides for 2-3 minutes or until bread is at desired level of golden brown. Enjoy.