1. Preheat the oven to 425˚F (220˚C).
2. In a large bowl, rub together the self-raising flour and cubed butter until you form fine crumbs.
3. Mix in the sugar, baking powder, and salt, and make a well in the middle.
4. Pour in the milk and gently mix together until just combined.
5. Tip the dough onto a floured surface and knead for about a minute. Be careful not to over-knead the dough.
5. Using a round cookie cutter or the rim of a glass, cut circles into the dough that are about 1-2 inches thick.
5. Place onto a baking tray lined with parchment paper and coat the tops of the scones with the egg yolk.
5. Bake for 12 minutes. Serve with clotted cream and jam.
Credit : https://tasty.co