01 -
Set the oven to 425 degrees F. Lay the puff pastry sheet on a baking sheet lined with parchment paper. Use a fork to poke holes all over to keep big bubbles from forming.
02 -
Slice the tomatoes thin. Put them on paper towels, sprinkle with kosher salt, and wait five minutes so the water comes out. Then blot them dry with more paper towels.
03 -
Spread pesto evenly on the pastry but leave about an inch without. Add the tomato slices next, then scatter the mozzarella over the top.
04 -
Use the beaten egg mix to paint the outer inch of the puff pastry so it turns glossy and golden when baked.
05 -
Slip it into the oven and bake for 20 to 25 minutes until the pastry is puffed up and golden.
06 -
Take it out of the oven. Drizzle some more pesto and balsamic glaze on top. Scatter fresh basil and sprinkle parmesan cheese. Cut into slices and enjoy while warm.