Preheat oven to 425 degrees Fahrenheit
Mix flour, sugar, baking powder & salt in a bowl
Use a cheese grater to grate in the cold butter, mix the dry ingredients with the cold butter so it's coated
Add the sourdough discard and sour cream to the bowl, mix dough together. Add milk if the dough is too dry, 1 Tbsp at a time. Dough should hold together, but not be sticky.
Turn dough out onto a pastry mat and gently bring dough together. Shape into a circle.
Press blueberries (or other topping) into the dough
Cut dough into 8 pie pieced shapes
Place the scones on a baking sheet
Brush with milk and sprinkle with a light dusting of sugar
Bake for approximately 15 minutes or until edges are golden brown