For the pastry, mix the flour with the butter until it resembles fine breadcrumbs, add beaten egg, a pinch of salt and a little water, starting with about 1 tbsp.
Bring it all together into a ball, knead it a little and leave to rest in the fridge while you deal with the filling.
For the filling, finely crush the seeds from the cardamom pods in a pestle and mortar and mix with the caster sugar.
Peel 2 large cooking apples, keeping the peel, and slice thinly.
Roll out the pastry and line a 25cm tart tin.
Arrange apples in neat concentric circles and evenly sprinkle over the cardamom sugar.
Bake in the oven at 160C/Gas 3 for 30 mins.
Finally, to make a glaze to brush over the finished tart, melt the caster sugar in a small pan with all the left over apple peel and some lemon rind until you get a sugary syrup.
Use a brush to paint it (minus rind bits) over the top of the tart when it is ready and cooled.
Recipe by appetite magazine at https://www.appetitemag.co.uk/apple-and-cardamom-tart/