Slice the pork loin into thin cutlets, trimming any fat and grizzle.
Place the cutlets under a sheet of plastic wrap and hammer thin with a mallet
Whisk together the marinade ingredients in a large bowl then fold in the meat. Cover the bowl with plastic wrap and refrigerate for at least 4 hours.
Preheat the oven to 400F
Poke a 10" or larger skewer through the half onion and place it flat side down in a large oven safe pan
Layer the meat on the skewer pressing occasionally to keep tight
If necessary add extra skewers at an angle to help sturdy the meat pile
Roast the meat at 400F for 2 hours.
To assemble the sandwiches carve off some meat, then fry it briefly and add it to a grilled pita with desired toppings.