Heat the air-fryer to 190C. Tip the oil, onion and garlic into a heatproof dish and air-fry for 3 mins. Add the tomatoes and chilli flakes, if using, along with some seasoning. Air-fry for a further 5 mins.

Reduce the temperature to 170C. Stir in the cooked pasta, tuna, most of the mozzarella and the parsley. Scatter the reserved mozzarella over the top.

Air-fry for 5 mins until golden, then cover with foil and cook for a further 5 mins until bubbling. Serve warm with salad.