Heat the oven to 200C/180C fan/gas 6. 

Unroll the pastry, cut into six squares and arrange over two baking trays lined with baking parchment. 

Use a cutlery knife to score a 1cm border around the edge of each pastry square. 

Bake for 15 mins, until puffed up but not cooked through. While the pastry cooks, mix the tomato purée, tomato ketchup, oregano and 1 tbsp water. 

Grate the cheese and chop any veg or herbs you want to put on top into small pieces. 

Remove the pastry from the oven. sprinkle with the cheese, then add your toppings. 

Bake for another 5-8 mins and serve.