Spread the first puff pastry crust dough in a large baking pan.
Using a small spoon, spread the pesto sauce on the puff pastry dough, leaving plenty of room along the edges.
Moisten gently the edges of 1st pastry dough with some water, using your fingers.
Carefully place the 2nd puff pastry dough on top of the 1st puff pastry, enclosing the pesto sauce in the middle.
Roll and enclose the edges together to form a crust, like you would for pizza dough.
Place a glass on top in the center.
Away from the glass, using a sharp knife, cut the pastry dough into 4 equal quarters.
Then cut each quarter in half, then each eighth in half, to make 16 equal strips.
Preheat the oven to 400°F (200°C).
Remove the glass and start to twist strips twice keeping the ends pinched together all the way around to make a pinwheel.
Crack the egg open in a bowl, and using a pastry brush, lightly paint the egg across the pinwheel.
(Optional) Sprinkle some sesame seeds across the pinwheel.
Place the tarte soleil in the oven for 20 minutes or until the dough rises and it looks cooked.
Serve while warm.