Preheat the oven to 220C (425F).

Sift the flour, baking powder, sugar and salt into a mixing bowl.

Add the grated frozen butter, grated cheddar and cream cheese and use two forks to toss and combine.

Gradually add the sourdough starter and use the forks to stir it into the dough. Keep adding as much starter as you need until the dough is crumbly and holds together in clumps.

If the dough is still too dry, stir in the soured cream or a little buttermilk. If the dough is too sticky add a little more flour, a tablespoon at a time and flour your worktop when rolling.

Tip the dough onto the worktop and pat into a rectangle. Fold the dough a couple of times.

Pat dough into a rectangle 2 inches high. Use a bench scraper to cut the dough into 6 chunky squares.

Space the scones out onto a lined baking sheet. Brush the tops of the scones with cream or buttermilk and sprinkle with the mixed herbs (you can also top with some grated cheddar if you like)

Bake the scones for 18-20 minutes or until golden and flaky.

Cool on the tray for 10 minutes then split and serve warm with salted butter or cream cheese.