Preheat the oven to 180°c (fan assisted)/390°f/gas 6.

Roll the puff pastry sheet out on a baking tray and cut it into the biggest circle you can (don't throw the leftover pastry away - you can use it to make mini tarts or pesto straws!). Use a knife to create an indent about 1.5cm in from the edge of the pastry, around the whole circle, to create the crust.

Spread the pesto all the way up to the crust, then lay the tomatoes, in a spiral, over the top. Use a pastry brush to glaze the whole tart with a little olive oil, then sprinkle with salt and black pepper and bake for 25-30 minutes, or until the pastry around the edge is lovely and golden.