In a bowl combine the flour, baking powder, and salt and stir.
Chop the cold butter into cubes and add it to the dry ingredients.
Use a pastry cutter to cut the butter into pea-sized crumbs, ensuring the pieces stay cold and don’t melt into the flour.
Stir in the grated cheese and chopped chives.
Add in the sourdough discard starter and half the milk.
Fold it together and add in only as much milk as is needed to create a shaggy dough that just holds together when pressed.
Tip this dough out onto a lightly floured bench and push it into a shaggy rectangle of about 7x10 inches (17cm x 25cm).
Lift up the bottom third of the dough and bring it into the middle.
Bring down the top third of the dough and fold this over, like you're folding a pamphlet.
Turn the dough 90° so it's lengthwise in front of you, then push or use a rolling pin to gently push it into another 7x10 inches (17cm x 25cm) rectangle.
Repeat the folding process once more.
Cut it into 8 pieces for large scones or 12 pieces for small scones.
Place the cut scones into the fridge for at least an hour, but up to 24 hours.
Preheat the oven to 428°F/220°C regular oven.
Brush the scones with milk and top with grated cheese.
Bake for approximately 14-20 minutes until golden brown.
Serve the scones hot with a pat of butter.
