1. Heat the sunflower oil in a large saucepan over a medium-high heat. Sauté the onion and garlic for 5-6 mins, stirring occasionally, until the onion starts to brown. Add the beef mince and increase the heat. Cook for 3 mins, stirring continuously to break up meat, until browned all over.
2. Stir in the cumin, paprika, chilli powder and tomato purée, and cook for a further 1 min. Add in the chopped tomatoes, kidney beans and stock, stir and bring to the boil, then reduce to a simmer for 20 mins until thickened, stirring occasionally.
3. Remove from the heat, stir in the chopped coriander and season to taste. Preheat the grill to high. Spoon the beef filling into the centre of the tortillas. Scatter half the cheese down the filling, then fold the sides of the tortillas in to create the burritos. Arrange them closely together on a baking tray and top with the remaining grated cheese.
4. Grill for 1-2 mins until the cheese has melted and the filling is hot, then transfer to serving plates. Serve with the lettuce, tomatoes and a dollop of soured cream, if liked.

Tip: The filling can be made a day in advance – the flavours will develop further if left overnight. Cook the filling as per the recipe and allow to cool completely. Transfer to an airtight container and chill in the fridge until needed. Preheat the oven to gas 6, 200°C, fan 180°C. Fill the tortillas with the cold beef mixture and cheese, as per the recipe, and place on a baking tray. Cook for 10-12 mins until the filling is piping hot and the cheese has melted. If the tortillas start to brown too quickly, place a piece of foil over the top.