Combine currants and 1/4 cup boiling water; let stand 10 minutes. Drain well, and set aside.
Combine 2 cups flour, baking powder, salt, and brown sugar in a medium bowl; cut in butter with a pastry blender until mixture resembles coarse meal. Add reserved currants and almonds; toss well. Add buttermilk to dry ingredients, stirring just until dry ingredients are moistened.
Sprinkle 1 tablespoon flour evenly over work surface. Turn dough out onto floured surface, and knead 3 or 4 times. Pat dough into an 8-inch round on a greased baking sheet. Cut round into 8 wedges, cutting to, but not through, bottom of dough. Combine beaten egg and 1 teaspoon water; mix well. Brush wedges with egg mixture, and sprinkle evenly with 1 tablespoon sugar. Bake at 425° for 10 to 12 minutes or until golden.