Place a large non-stick saucepan over a medium heat and add the beef and onions. Cook together for 5 minutes, stirring the beef and squishing it against the sides of the pan to break up the lumps. Add the garlic, 1–2 teaspoons of chilli powder, depending on how hot you like your chilli, and the cumin and coriander. Fry together for 1–2 minutes more. Sprinkle over the ﬂour and stir well.