Preheat your oven to 180C.
Pour your try ingredients into a bowl and stir to combine.
Add your cubed butter. Pinch and rub with your fingertips to form crumbs.
Sprinkle in your cheese and chopped three-cornered leek and stir to combine.
Make a little well in the middle and pour in your milk, a little at a time, mixing regularly. You might not need to use all the milk to get a smooth dough, so don’t pour it all in at once.
Lightly flour a surface and roll out your dough- you want it to be about 2cm thick. Use a cutter to cut out rounds, score a cross on the top and place on a lined baking tray.
Brush a little milk over the top of each scone to glaze. You can also sprinkle a little cheese over the top if you’d like.
Bake for 15-20 minutes, until golden brown and cooked through.