Wash the potatoes and dry them well. They can absolutely keep their skins on.
Toss them in the oil and season with salt and pepper.
Place them in a heatproof dish and cook them for 30 minutes at 200 degrees Celsius (392 degrees Fahrenheit) with convection.
Take the potatoes out and flatten them with a wooden spoon, then give them another 30 minutes at 200 degrees Celsius (392 degrees Fahrenheit) with convection.
The reason for flattening (bashing) them is to create more surface area for a crispy crust.
