Butterfly the pork tenderloin and pound it to a 1/2-inch thickness. Place the pork in a shallow dish. Cover with the olive oil, orange juice, lime juice, and garlic; turn to coat. Cover and refrigerate at least 1 hour.
Remove the pork from the marinade and place it on a cutting board. Spread the pork with mustard, then layer it with ham and Swiss. Scatter the pickles over the cheese. Starting at the long end, tightly roll the pork around the filling; secure with kitchen twine or toothpicks.
Heat your grill to high. Place the pork onto the grill, seam-side down. Cook for 4 minutes on each side, until browned. Reduce heat to medium low; cook the pork loin over indirect heat for 20 minutes, or until it reaches an internal temperature of 150-155 degrees. (You can also make this stuffed pork loin in the oven: Bake it for 10 minutes at 450 degrees, then cook at 350 degrees for 45-55 minutes or until it's cooked through.)
Remove the pork tenderloin from the grill and tent it with foil. Let it rest for at least 5 minutes, then remove the twin and slice into rounds.