Use the pastry recipe from Anchovy and Onion Tarts but instead of forming an irregular square shape, make circles that measure 15 cm/6 inches in diameter.
Preheat the oven to 425°F/220°C/Gas Mark 7. Thinly slice the tomatoes. If they are exceptionally juicy, lay them on a tea towel for a few minutes to soak up the excess juice. Grease a flat baking sheet and lay out the pastry circles. Lightly prick the pastry with a fork but not quite t