Preheat the oven to 375 degrees, and line a baking sheet with parchment paper.

Combine the flours, sugar, baking soda, and salt in the bowl of an electric mixer with a paddle attachment. Add the butter and mix on low until the butter is mixed into the dry ingredients.

In a separate bowl, beat the buttermilk, egg, and orange zest together, and with the mixer on low speed, slowly add the buttermilk mixture to the flour mixture.

Shake the currants with 1 tablespoon of flour and mix into the dough. The dough should be quite wet.

Put the dough on a floured board and knead lightly into a round loaf. Place the loaf on the prepared sheet pan, and lightly cut an X into the top of the bread.

Bake for 45 - 55 minutes, or until a cake tester comes out clean.

Serve warm or at room temperature.