Preheat the oven to 220°C (200°C fan/425°F/Gas 7).
Unroll the pastry and slather with a thick layer of cream cheese leaving a small border around the outside. Lay it out on a tray and set aside.
Spread the pesto all over the baking tray.
Lay the mushrooms onto the tray in tightly packed rows so that you form a rectangle 2cm smaller that the size of pastry sheet.
Drape the pastry, cheese-side down onto the mushrooms. Using the back of a spoon or fork, press indentations around the edge of the pastry to seal.
Score the top in a diamond pattern with a sharp knife and then brush with egg.
Bake for 30–35 minutes, until the pastry is golden and crisp.
Remove from the oven and allow the tart to sit on the tray for 5 minutes before laying a board on top and flipping over. Peel back the baking paper to revel the tart.
Divide into portions and lay a fried egg on top of each.
