Peel the applies and cut them into strips or small pieces (to taste), put them in a bowl and add the lemon juice.
Add the white sugar, brown sugar, cinnamon, nutmeg and salt to the apples. Stir well to mix the ingredients, cover with plastic wrap and leave to marinate in the refrigerator for 30 minutes. After this time, take the bowl out of the refrigerator.
Extend the pastry over a baking tin, sticking it to the sides and removing the excess with a knife.
Preheat the oven to 392ºF and continue with the filling.
Separate the apples and pass the remaining liquid through a strainer. Heat this liquid with the oil until obtaining a syrup.
Add the corn starch to the apples, stir well, then add the syrup, mixing again so that everything is well combined.
Put the apples in the baking tin on top of the pastry, finishing by covering the pie fully, or making a lattice top.
Once covered, brush the surface with a little milk and dust with sugar. Bake for 15-20 minutes, then reduce the temperature a little (356ºF) and allow it to finish cooking, turning the top golden.