Cut in the butter until the mixture resembles large crumbs.
In a separate bowl, beat the remaining two eggs and stir in the cream. Then stir the egg-cream mixture into the dry ingredients. Stir in the currants.
Turn the dough out onto a floured board and press it together into a single lump. If it doesn't hold together yet, add more cream, a tablespoon at a time, until it does. Don't overwork the dough, though.
Roll the dough out to a thickness of 1 inch. Cut into rounds with a round or fluted pastry cutter. Or you could cut the dough into triangular wedges, which will reduce the amount of scraps you end up with.
Arrange the scones on your prepared baking sheet. Brush the tops of the scones with the egg white, and transfer the pan to the oven. Bake 15 minutes or until golden.