Preheat the oven: preheat the oven to 180°C / 350-375°F / Gas Mark 4-5.
Filling: add the pulled pork, diced onion, black beans and corn to a large mixing bowl and stir gently to combine.
Roll: next place the tortillas onto a large plate and microwave on high for 10 seconds to soften them. Next working one at a time place the tortilla into the middle of a clean, dry cutting board, Spoon the filling into the center then roll and set aside. Repeat this process for all 10 tortillas.
Assemble: liberally spray a large baking dish with cooking oil. Then pour a small amount (approx ¼ cup) of the sauce into the base of the dish and use a rubber spatula to spread it out across the base of the dish. Next transfer each rolled enchilada into the base of the dish (on top of the sauce) and gently push them to the side to fit all 10.
Sauce and cheese: now pour the rest of the sauce over the top and use the spatula to spread the sauce out across the top of the enchiladas. Once done sprinkle the cheese over the sauce.
Oven bake: take the baking dish and place it into the oven (uncovered, middle shelf). Bake the enchiladas for 15 minutes until the cheese melts and turns a little golden brown.
To serve: use oven mitts to remove the baking dish from the oven and set it on a heatproof surface. Let i cool for 5 minutes and use this time to garnish with freshly chopped herbs. Serve with your favorite toppings.