Preheat the air fryer to 180C.

Carefully slice the potatoes with lots of incisions, taking care to just go ¾ way through.

Brush with oil and generously season with salt.

Place in the air fryer and cook for around 30 minutes - or until golden, crisp and soft in the centre (the exact time will depend on the size of the potatoes).

Meanwhile, place a medium-sized non-stick frying pan over a medium-high heat and add a generous drizzle of olive oil. Add the prosciutto in a single layer and fry for a couple of minutes on each side until crispy. Remove from the pan and set onto a plate lined with kitchen paper to drain off any excess oil.

To serve: tip the warm potatoes onto a plate, crumble over the crispy prosciutto and sprinkle with the spring onions, chives and dried chilli flakes, if wished. Serve with the sour cream to dip.