Lightly grease your pie pans, then line with the defrosted puff pastry [Note 1]. Trim around the outer edge of the pie pan to remove excess pastry, and use this to fill in any gaps if needed. Refrigerate the lined pie pans while you mix the fillings.
Whisk the eggs, mustard powder and salt in a bowl or large mixing jug [Note 2]. Add the shredded cheese and the other filling ingredients and mix until combined.
Preheat air fryer to 320°F/160°C.
Remove pastry-lined pan(s) from the refrigerator. Gently prick the pastry at the bottom of the pan [Note 3].
Carefully pour the quiche filling mixture into the pie pan. Do not over-fill it, be sure to leave at least ¼ inch of space at the top.
Place the quiche in the air fryer basket (take care as air fryer basket will be hot). Air fry quiche for: - 20 minutes for individual quiches - 25 minutes for a single 8inch/20cm quiche
Quiche is done when the crust and the top are golden brown, and it has reached 160°F/ 72°C [Note 4].
Leave the quiche to set for at least 10 minutes (or longer if you want to cut nice clean slices).
Notes
You will need either 4x 4½ inch/ 10-12cm pie pans, or a single 8 inch/ 20cm pie pan.
Use a mixing jug if you have one large enough as it makes it much easier to pour the filling into the pan when it is ready.
You want to break the surface of the pastry, but not go all the way through to the pan.