Slice the onion into thin slices. In a medium hot pan, pour the oil and it heats up, scatter the sliced onion along with ½ teaspoon salt. Stir and let it cook until it’s caramelized. Once done keep it aside to be used later.

Preheat the oven to 400 F

Flatten the puff pastry sheet on a cookie sheet and leaving ½ inch area from the edge score gently all the four sides. Using a fork poke several times inside the scored line. Bake the sheet in a preheated oven for 15 minutes.

The entire sheet might puff up, so as soon as it’s done, take it out of the pan and press the center using the bottom of a glass or measuring cup to flatten it out.

While the sheet cools down a little, spiralize the zucchini. You could also just use a vegetable peeler and make zucchini ribbons. Or keep it extremely simple by just slicing the zucchini into thin circles.  

In a bowl whisk the sour cream with the egg, rest of the salt, paprika and fresh thyme leaves.

Spread the sour cream mixture on the puff pastry, stay inside the scored area. Layer the zucchini along with the zucchini flowers if using. Then scatter the caramelized onion.

Crack another egg in a bowl and whisk it. Then brush the sides of the puff pastry with the egg.

Bake in preheated 400 F oven for 15 to 17 minutes, or untilthe sides are golden brown.

Once done, take it out of the oven and grate some parmesan cheese on top. Let it cool for 5 minutes then slice and serve.