Heat oven to 375˚ F.
Combine flours, baking powder, baking soda, nutmeg, and salt in large bowl. Cut in butter until mixture is the texture of course bread crumbs.
Add currants, walnuts, and 2 tablespoons sugar and toss to mix evenly.
Stir in buttermilk with a fork until a soft dough forms.
Shape dough into a ball on a lightly floured surface. Divide into 2 parts and shape into 2 round balls.
Press into 6-inch rounds and place on an ungreased cookie sheet. Cut each round into 6 wedges, but do not separate the wedges. Brush with beaten egg white and sprinkle with 2 teaspoons sugar.
Bake for 20 to 22 minutes until golden brown. Break into wedges and serve warm.
TIP: If necessary, add 1 to 2 tablespoons water to moisten all of the flour.