Place the oil, paprika, garlic, vinegar, oregano and some salt and pepper in a large mixing bowl. Add the pork and mix well to coat. Cover with clingfilm and refrigerate for at least 4 hours (or overnight) to marinate.
Preheat the oven to 160 °C. Place the pork in a baking dish and add the water to the dish also. Cover with foil and cook for 4 ½ hours, or until the meat is tender and falling apart.
Remove the meat to a board and shred, discarding any fat.
Combine all the sauce ingredients together in a saucepan. Heat over a low heat for 10-15 minutes, stirring occasionally, until slightly thickened.
Add the shredded pork and the sauce to a bowl and toss to combine.
Grill the burger buns and then top with some shredded pork and some fresh coleslaw to serve.