Preheat oven to 400°F. Spray an 8-9" pie dish, cake pan, or cast iron skillet with non-stick spray and set aside. You may also line a baking sheet with parchment or a silicone baking mat.
In a medium-sized bowl, whisk together the flours, sugar, baking soda, salt, and currants or raisins. Using a pastry blender or a fork (even just your fingers), cut in the butter until pea-sized chunks have formed.
In a separate bowl (or in a measuring cup with a spout), whisk together the buttermilk and egg. Pour mixture into the dry ingredients and mix with a spatula to combine. The dough will be stiff but you will be able to squeeze it together with your hands easily. Keep pushing dough together until all dough bits and currants are mixed in.
Knead the dough a few times with your hands and shape into a ball. Place dough ball into prepared pan and flatten slightly. Use a sharp knife to cut a 1/2-inch deep "X" across the top of the loaf.
Bake 45 to 50 minutes, until it is golden brown. Loaf should sound hollow if you carefully remove it from the pan and tap on the underside of the loaf. Allow to cool on a wire rack. Serve warm with butter or jam. I enjoy mine dunked in a cup of coffee. Once completely cool, bread will keep well in an airtight container at room temperature up to 3 days.
If you don't have or don't want to use either of these flours, you may use entirely all-purpose or any combination of the flours you have available. Total flour is 3 and 3/4 cups.