In a large, non-stick frying pan, dry fry the beef, onion and garlic for about 5 minutes until the beef is browned and broken up.
Add the kidney beans, tomato puree and chilli flakes to the pan and give it all a good stir to combine. Stir in the beef stock and bring to a simmer. Continue to cook for 25 to 30 minutes until the mince is tender and the sauce has reduced and thickened.
Preheat the oven to 200 C / Gas 6 and lightly brush a baking dish with oil.
Take a tortilla and spoon an eighth of the mince mixture down the middle. Fold over one side and then fold the ends in and roll up to enclose the filling. Place in the baking dish, seal side down, and repeat with the remaining tortillas.
Drizzle over any sauce you like. There are recipes on this site for enchilada sauce but I like to use about 150g of pasta sauce from a jar. Evenly sprinkle over the cheese and place on the top shelf of the oven.
Bake in the oven for 15 to 20 minutes until the sauce is heated through, the cheese has melted and the edges of the tortillas are crisping up. Serve hot, 2 tortillas per person.