Peel the onions, cut in half and thinly slice.

Melt the butter in a frying pan, add the onions, season with salt and pepper and cook on a low heat to soften for 10 minutes. Set to one side to cool once cooked.

Meanwhile, crack 1 egg into a medium sized bowl and whisk in the milk.

Add your cooked onions to the egg mixture, along with the grated cheese.

If you’re using a CRIMPiT, roll out your pastry, place the CRIMPiT on top and cut around it so you have a circle of pastry, the same size as your CRIMPiT. If you’re doing this without one, you can just cut your pastry into 4 sections and make 2 pastries (or 1 big one if that’s what you fancy 😂) If using this method, use a piece for bottom, and a piece for the top. Use a fork to seal the edges or pinch with your fingers.

Place half of the onion mixture onto one side of the pastry in the CRIMPiT and close the CRIMPiT to seal (push down firmly to ensure a tight seal). Use the off cuts of mixture to make mini pastries, be experimental with the shapes!

Transfer the pastry to the air fryer, brush with egg wash and air fry for 18 minutes at 180ºC.