Place 2 puff pastry sheets on a silicone-lined baking sheet, overlapping the short ends to form a rectangle. Trim seams from 2 more sheets and press along the edges to form a raised border.
Freeze dough until firm, about 10 minutes
Score border with a knife, making shallow cuts 1/4-inch apart. Press the bottom of a fork onto the seam in the middle and poke holes all over the base
Bake tart shell until lightly golden and partially puffed, about 10 minutes. Press down on the base using the bottom of a fork. Avoid pressing border. Let cool for 10 minutes
Spread mustard over the base. Arrange tomato slices in a single layer, cutting some to fill gaps. Season with salt, pepper, and herbes de Provence. Top with Parmigiano-Reggiano and drizzle most of the olive oil.
Bake at 400°F for 25–30 min until golden and crispy. Cool on the sheet or transfer to a rack. Drizzle remaining oil and sprinkle fresh oregano, parsley, and thyme before serving.
Ingredients
1 sheet frozen puff pastry, thawed and cut into quarters
