For the salsa, coarsely grate the tomatoes into a bowl, discarding any skin left behind, then grate in the onion. Stir in the olive oil, lime juice and chilli powder, if using, and a pinch of salt, then set aside. Can be made a day ahead and chilled.

Tip the beans into a bowl with the Cajun seasoning and the rest of the lime juice, then use a potato masher to roughly mash. Line the air fryer basket with baking parchment. Layer in half the tortilla chips, half the beans and half the cheese, then repeat to make a second layer.

Air-fry at 200C for 8-10 mins, or until the cheese is melted, golden and bubbling. Use the sides of the parchment to lift the nachos onto a platter, then spoon over half the tomato salsa and scatter over the coriander, if using. Serve with the rest of the salsa on the side.