First of all, properly wash the 1 Kg granny smith apples, which are green in colour. Now, carefully peeled them, core, and cut them into thin wedges.
Take a saucepan and add in the granny smith apples’ wedges, 1/4 cup water, and 1/2 cup caster sugar. Mix them and cook them over medium heat for two minutes or until the caster sugar dissolves and the apple slices just tender. Do not forget to stir the mixture from time to time. Now, set your apple mixture aside at room temperature until cool completely.
Now, start lining the bases and sides of four round pie tins. Half fill the tins with the pastry and place them in your refrigerator for approximately 15 minutes.
Remove the pie tins from refrigerator and brush their edges with one lightly whisked egg. Now divide the apple-sugar mixture equally among the pastry cases with the help of a slotted spoon.
Grab a round pastry cutter, cut four discs from your remaining pastry, and use them to top the four pastry cases.
Press the edges of the pies with a fork and seal. Trim the excess pastry with the help of a small sharp knife and cut a small cross in the top of the four pies.
Brush the tops of the four pies with the remaining egg and carefully sprinkle with white sugar.
Place your Apple pies on a baking tray and bake them in a 200°C pre heat oven for around 25 to 30 minutes or until golden. Your Apple pies are ready to serve.