Chef John's Caramelized Tomato Tart

Preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius).

Place two sheets of puff pastry on a silicone-lined baking sheet. Press the short edge seam from one piece onto the other to create the base of the tart, forming a rectangular shape. Cut the edges off the remaining two pieces and attach them to the base as a border.

Allow the dough to firm up in the freezer for about 10 minutes.

Score the border with a knife, making shallow cuts approximately one-quarter inch apart. Use the bottom of a fork to press holes into the base, creating a textured surface.

Bake the tart shell until it's lightly golden and partially puffed, taking about 10 minutes. Use a fork to gently press down on the base, avoiding the border area. Allow it to cool for 10 minutes.

Spread a layer of mustard onto the interior surface of the tart. Arrange tomato slices in a single layer on top, cutting some into halves to fill gaps and create a uniform appearance. Season with salt and pepper, then sprinkle herbes de Provence liberally over the top.

Add a generous amount of Parmigiano-Reggiano cheese and drizzle most of the olive oil over the tart. Place it in the preheated oven and bake until the pastry is well browned and crispy, taking 25 to 30 minutes. Remove it from the oven and let it cool to room temperature on the baking sheet or transfer it to a wire rack using two spatulas. Drizzle any remaining olive oil over the tart and sprinkle fresh oregano, parsley, and thyme on top.