To make the pastry:
1. Mix flour and caster sugar, add warm water and knead until smooth dough.
2. Make pastry: Mix flour with lard or butter and knead into pastry dough.
3. Wrap the pastry: Roll out the oil dough, wrap it in the pastry dough, and seal the mouth.
4. Roll out and fold: Roll out the dough into a square shape, fold it into three layers, repeat this step twice, then roll out into a round piece.
#### To make the egg yolk filling:
1. Prepare the bean paste filling: If you use the commercial bean paste filling, you can use it directly; If you make your own, prepare it in advance.
2. Wrap egg yolk: Take proper amount of bean paste and wrap a cooked salted duck egg yolk into a ball.
#### egg yolk crisp:
1. Divide the pastry: Divide the rolled pastry into small pieces, about 30g each.
2. Filling: Roll the small dosage into a round piece, wrap it in the egg yolk filling, seal and pinch tightly.
3. Shaping: Gently flatten the filling dough and arrange it into a circle.
