Preheat the oven to 180°C/160°C fan/350°F. Line a baking tray with baking paper. Weigh the flour, baking powder, caster sugar and salt into a large mixing bowl and stir to combine thoroughly.
Chop the butter into cubes and rub into the flour mixture until it has the texture of fine breadcrumbs. Stir in the grated cheese.
Mix the cream and milk in a jug and pour most of it into the bowl, bringing the dough together with a wooden spoon. Add the rest of the milk if it seems dry. Tip the dough onto a floured surface and quickly but gently knead it together then flatten it into a rectangle with a rolling pin. Cut the dough in half lengthwise then cut each half into four. Line them on the baking tray and top with extra grated cheese.
Put the tray in the oven and bake for 20-25 minutes until the tops are golden brown, the scones are well-risen and sound hollow when tapped on the base. Best eaten warm with a little butter.