Step 1

Slice each leek lengthways, then into semi-circles about ¾ in. thick. Rinse, then place into a heatproof dish that fits in your air-fryer. Add the butter and salt to the dish. Preheat the air-fryer to 350ºF. Add the dish to the preheated air-fryer and cook for 15 minutes, stirring twice during cooking.

Step 2

Place the stale bread in the base of a heatproof dish that fits in your air-fryer. Add the cooked leeks and ham to the bread, then add the black pepper over the top.

Step 3

In a bowl mix together the eggs, cream, milk, mustard powder if using and Parmesan and pour this into the dish. Pour slowly and make sure the mixture gets into all the nooks and crannies.

Step 4

Preheat the air-fryer to 325ºF. Add the dish to the preheated air-fryer and cook for 12–14 minutes. After 7 minutes, sprinkle the grated Cheddar over the top and continue to cook. Serve hot or cold.