Preheat the oven to fan 170C/ conventional 190C/gas 5. Roll out the pastry on a lightly floured surface so it’s slightly thinner than straight from the pack. Then cut out 18-20 rounds with a 7.5cm fluted cutter, re-rolling the trimmings. Use the rounds to line two deep 12-hole tart tins (not muffin tins). If you only have a regular-sized, 12-hole tart tin you will be able to make a few more slightly shallower tarts.