Preheat oven to 400° F.
Wash the Black Currants and mix them with the sugar and flour.
Roll out half the pastry and use it to line an 8 1/2-in, greased, deep pie pan.
Fill the plate with the currant mixture and roll out the remaining pastry to form the top.
Moisten the edges of the pastry on the dish and cover with the top pastry, pressing the edges well together.
Scallop the edges, cut slits into the center with a knife and brush the top with milk. Place the pie pan on a baking sheet and bake in the oven at for about 30 minutes.
Remove the pie from the oven, cover it loosely with foil to prevent over-browning, return it to the oven and bake for 30 minutes more.