Preheat and Prepare the Tin: Preheat your oven to 180°C (160°C fan). Lightly grease a 12-hole standard muffin tin with a little oil or cooking spray.

Sauté the Aromatics: Heat the olive oil in a large frying pan over a medium heat. Add the finely chopped red onion and cook for 4-5 minutes until it has softened. Add the minced garlic and cook for another minute until fragrant.

Brown the Mince: Add the lean beef mince to the pan. Break it up with a wooden spoon and cook for 5-7 minutes, until it's browned all over. Be sure to drain off any excess fat that has rendered out.

Add Spices and Simmer: Stir in the tomato purée, smoked paprika, ground cumin, dried oregano, and chilli powder. Cook for one minute, stirring constantly, to toast the spices. Pour in the beef stock, season with salt and pepper, and bring to a simmer. Reduce the heat and let it bubble gently for 5-8 minutes, until most of the liquid has been absorbed and the mixture has thickened. Set aside.

Form the Tortilla Cups: While the mince simmers, prepare your cups. Use a 10cm (4-inch) round cutter or a small bowl as a guide to cut two circles from each large tortilla, giving you 12 circles in total. Gently press each tortilla circle into a hole in the prepared muffin tin, pleating the sides as needed to form a cup shape. What works best for me is using the bottom of a small glass to gently press the tortilla into place.

Pre-Bake the Cups: Place the muffin tin in the preheated oven and bake for 5-7 minutes, or until the tortilla cups are lightly golden and firm. This step is crucial for a crispy final product.

Fill and Bake: Carefully remove the tin from the oven. Divide the cooked beef mince mixture evenly among the pre-baked tortilla cups. Top each cup generously with the grated cheese.

Final Bake: Return the tin to the oven and bake for another 8-10 minutes, or until the cheese is melted and bubbling and the edges of the tortilla cups are deep golden brown. Let them cool in the tin for a few minutes before serving, as they will be very hot.