Preheat oven to 425°.
Combine flours, baking powder, sugar and salt in a bowl and whisk together.
Slice butter and drop into dry ingredients. If you have a pastry cutter, use it to cut the butter into the flour. If you don’t have a pastry cutter, use a knife to cut the butter into tiny pieces and mix it into the flour.
Add blueberries and lemon zest and gently stir. You can use frozen blueberries, no thawing necessary.
Gently mix in milk and yogurt. Eventually you’ll need to use your hands to knead the last of the flour into the dough.
Form dough into a circle about that’s about an inch deep all around. Cut the circle into 8 slices.
Separate slices and place on a baking sheet covered in parchment paper or foil.
Bake for 15 minutes or until light brown