Summarize the following:
Stir these dry ingredients a few times with a wooden spoon to combine them. Scoop 1 cup of the dry mixture into the sifter or sieve. Continue sifting the dry ingredients 1 cup at a time until all of them have been sifted together. Make sure to place a plate beneath the grater to catch the frozen butter pieces. Using clean hands, mix the butter pieces into the flour mixture until the dry ingredients begin to resemble coarse crumbs. Mix the ingredients well using a wooden spoon. Wrap the disc in plastic wrap and chill it for 1 hour in the refrigerator.

Summary:
Pour the egg and the milk into a bowl and whisk them together until they are well combined. Add the currants to the egg and milk mixture. Combine the flour, sugar, nutmeg, baking powder, baking soda and kosher salt in a large bowl. Position a sifter or sieve over another clean bowl. Turn the handle of the sifter or tap the sieve until the dry ingredients pass through the mesh and into the bowl. Grate the frozen sticks of butter using the largest holes on a box grater. Add the grated butter to the bowl with the sifted dry ingredients. Pour the egg, milk and currant mixture over the flour and butter mixture. Shape the dough into a flat disc.