The base is puff pastry rolled into a rectangle. I use ready-made puff pastry because it’s too labour intensive to make my own. I score an inner rectangle about three-quarters of an inch in, and spread green pesto inside it. Then come the chopped tomatoes, the torn basil leaves and the crystals of sea salt. Finally I brush the edges outside the inner rectangle with beaten egg and bake it in a 170 fan oven for about 15 minutes. The result is a very tangy tomato tart.