Melt butter in a fry pan over medium heat. Add onions and cook for 7 minutes, stirring every now and then so they cook evenly. Add remaining Caramelized Onion ingredients and cook for a further 5 minutes, stirring occasionally until sticky and caramelised. Remove onion from pan and set aside.

Brown Pork Carnitas: Wipe pan clean and return to stove. Heat 1/2 tbsp oil over high heat. Add Pork Carnitas and press down lightly with a spatula to help crisp up. When the Pork Carnitas are heated through and the underside is golden brown and crisp (about 1 to 1/2 minutes), remove from pan (do not flip).

Place Pork Carnitas and Enchilada Sauce and mix to combine.

Preheat grill (broiler) on high.

Split rolls in half. Divide the Filling between them and pile onto the bottom half of the roll. Top with cheese then grill (broil) for 3 minutes until melted.

Remove from the grill, top with caramelised onion and sprinkle with parsley (if using).

Sandwich with the other half of the bread roll and serve immediately.