Preheat the oven to 180C/Gas 4 and line a large baking tray with greaseproof paper
Rub the butter into the flour until the mixture resembles fine breadcrumbs then stir in the Parmesan, olives and thyme
Clump the mixture together with your hands until it comes together into a crumbly dough
Break off a golf ball-sized piece of dough and flatten it onto the baking sheet so that the biscuit is 1cm thick
Repeat with the rest of the dough then bake for 15 minutes turning half way through
Transfer the biscuits to a wire rack and leave to cool completely
20 servings