Peel the potatoes, cut into 1-inch cubes, and place into a bowl of cold water to soak for 10 minutes.
Preheat air fryer to 360°F/180°C.
Drain the potatoes and pat them dry. Place in a large bowl, drizzle with oil, add the salt, and toss to coat.
Place the breakfast potatoes in the air fryer and cook at 360°F/180°C for 20 minutes, shaking the basket to redistribute the potato cubes 1 or 2 times during the cooking time [Note 2].
The potato cubes should be golden brown and crispy. Air fry for an additional 5 minutes if required.