These deliciously short little biscuits are terrific as nibbles or as additions to the cheeseboard
Makes about 20, about 400g
120g butter, chilled and cubed 250g plain flour, plus extra to roll out 60g Parmesan, finely grated 60g mature Cheddar cheese, finely grated 3 egg yolks 1 heaped tbsp coarse-grain mustard 1 tbsp milk
Step 1) In a large bowl, rub the butter into the flour until it resembles fine breadcrumbs; or use a food processor to pulse the flour and butter together, then transfer to a bowl.
Step 2) With a knife, cut all the cheese, 2 of the egg yolks, the mustard and 1-2 tbsp of cold water into the mixture. Use the knife to combine until the mixture begins to form a non-sticky dough. Go in with your hands and knead gently, but don’t overdo it or the biscuits will be tough. Form into a disc, wrap in cling film and chill for 30 minutes at least.
Step 3) Pre-heat the oven to 150°C, Gas Mark 2. Roll the chilled dough out on a lightly floured surface to about 1.5cm thick. Stamp out 6cm rounds, using biscuit cutters, and re-roll the trimmings to stamp out more. Space the biscuits out about 2cm apart on baking sheets. Combine the remaining egg yolk with the milk and brush over the biscuits to glaze. Bake for 20 minutes, or until crisp and golden. The biscuits will keep in an airtight tin for several days, or in the freezer for up to 6 months.