Set the oven to 220°C/425°F/Gas Mark 7.

Unroll the pastry and trim around the edges, discarding the trimmings. With a knife, score a line through the pastry, but not cutting all the way through, about 1-2cm inside the edge of the rectangle. Score the rim around the pastry edge in a criss-cross pattern, again, taking care not to cut all the way through. Slide the pastry on to a baking sheet.

Brush egg glaze around the edge of the pastry, taking care that the glaze doesn’t run down over the sides, otherwise the pastry won’t rise properly.

Spread the pesto over the pastry, inside the scored line. Arrange the tomatoes on top, cut-side up. Drizzle olive oil over and season with salt and pepper.

Bake the tart, at the top of the oven, for 20-30 mins, until the pastry is a golden colour and crisp at the edges, and the tomatoes have started to soften.