Preheat and prep your baking dish. Preheat your oven to 190°C (170°C fan). Lightly grease a 23cm x 33cm (or equivalent 3-litre) baking dish. You'll smell the warm metal as it heats, a sign that it's ready for action.

Cook the beef base. Heat the olive oil in a large frying pan over a medium-high heat. Add the chopped onion and cook for 4-5 minutes until it becomes translucent and soft, with a gentle, sweet aroma. Add the minced garlic and stir for 30 seconds until it releases its pungent scent. Add the beef mince, breaking it up with a wooden spoon. Cook for 6-8 minutes, stirring occasionally, until the beef is deeply browned. You will hear a satisfying sizzle and see the meat turn a rich, dark brown colour, with small crispy bits sticking to the pan. Drain off any excess fat if necessary.

Season the filling. Sprinkle the cumin, smoked paprika, oregano, black pepper, and salt into the pan. Stir well and cook for 1 minute until the spices become fragrant, filling your kitchen with a warm, earthy smell. Add the black beans and sweetcorn, stirring to combine. Pour in 200ml of the enchilada sauce, stir, and let it simmer for 2 minutes until the sauce thickens slightly and coats the meat. The mixture should look glossy and smell richly savoury.

Layer the first row. Spread a thin layer (about 3 tablespoons) of the remaining enchilada sauce over the bottom of the prepared baking dish. This prevents the tortillas from sticking. Arrange a layer of tortilla pieces over the sauce, overlapping them slightly to cover the base completely. You'll see the tortillas absorb the sauce and soften almost immediately.

Build the casserole. Spoon one-third of the beef mixture over the tortillas, spreading it evenly. Sprinkle one-third of the grated cheese on top. Drizzle with a little more enchilada sauce. Repeat this layering process two more times: tortillas, beef mixture, cheese, and sauce. For the final layer, place the last of the tortilla pieces on top, pour over the remaining enchilada sauce, and finish with the remaining cheese. The top should look like a patchwork of tortilla corners and bubbling cheese.

Bake to golden perfection. Place the dish in the preheated oven, uncovered, and bake for 25-30 minutes. You will see the cheese melt and bubble, and the edges of the casserole will start to bubble with the sauce. When it's done, the top should be golden brown and slightly crispy in spots, and the sauce will be bubbling vigorously around the edges. The smell coming from the oven will be irresistible—rich, spicy, and cheesy.

Rest and serve. Remove the casserole from the oven and let it rest for 5-10 minutes. This is crucial; it allows the layers to set, so you get neat slices rather than a soupy mess. The casserole will still be piping hot, but the cheese will have firmed up slightly. Garnish with fresh coriander and serve with soured cream or Greek yogurt on the side.