Slice the pork into chunky even pieces, removing any large pieces of fat.
Mix all the ingredients for the marinade in a bowl. Add the diced meat, mix to combine, cover and leave to marinate for 30-60 minutes in the fridge.
Grill the skewers
If you are using wooden skewers, soak them in warm water for 30 minutes so that they don't burn. Thread the meat on the skewers.
Heat a large frying or griddle pan and wipe with olive oil. Grill the skewers over high heat, turning frequently, for 8-10 minutes or until cooked through. Taste and season with additional salt (if needed) and pepper.
Serve the souvlaki
Mix the sliced onion with the chopped parsley and have all your souvlaki fillings ready.
Briefly pan fry the pitas to warm them up (or brush with a little olive oil and briefly grill on the barbecue) then add a little onion, tzatziki and sliced tomatoes.
Add the meat (off the skewers) and season with a little smoked paprika. Wrap the pitta around the fillings, using a little greaseproof paper to hold everything together if you like. Eat immediately!
Notes
You can use store-bought pita bread or make my super easy two ingredient flatbreads to serve your souvlaki with. If you wish to make yeasted pita breads then follow the recipe in this post.