Sauté the Aromatics: Heat 1 tablespoon of vegetable oil in a large frying pan over a medium heat. Add the chopped onion and cook for 5-7 minutes, until softened and translucent. Add the minced garlic and cook for another minute until fragrant.

Brown the Beef: Add the beef mince to the pan. Break it up with a wooden spoon and cook until it's browned all over. Drain off any excess fat from the pan.

Add Spices and Liquids: Stir in the ground cumin, smoked paprika, dried oregano, chilli powder, salt, and pepper. Cook for about a minute until the spices are aromatic. Pour in the chopped tomatoes and beef stock.

Simmer the Filling: Bring the mixture to a gentle simmer, then reduce the heat and let it cook for 10-15 minutes, stirring occasionally, until the sauce has thickened considerably. You want a rich, dense filling, not a watery one. Remove from the heat and allow it to cool for at least 10 minutes.

Warm the Tortillas: Gently warm the tortillas in a dry pan or in the microwave for 15-20 seconds. This makes them more pliable and less likely to crack when you fold them.

Assemble the Chimichangas: Lay a tortilla flat. Spoon about a quarter of the beef filling into the centre, leaving a border around the edges. Top with a generous handful of grated cheddar. What works best for me is to fold the two sides in over the filling first, then tightly roll from the bottom up to create a secure parcel, like a burrito. If needed, you can use a cocktail stick to hold the seam in place.

Heat the Frying Oil: Pour vegetable oil into a large, deep frying pan to a depth of about 2-3cm. Heat over a medium-high heat until it reaches about 180°C. If you don't have a thermometer, a small piece of bread dropped in should turn golden brown in about 30 seconds.

Fry to Perfection: Carefully place one or two chimichangas into the hot oil, seam-side down. Frying them seam-side down first helps to seal them. Fry for 2-4 minutes per side, until they are deep golden brown and crispy all over.

Drain and Serve: Use tongs to remove the chimichangas from the oil and place them on a wire rack to drain any excess oil. This keeps the bottom from going soggy. Serve immediately while hot and crispy.