3tablespoonsDijon mustard(grainy or smooth OR pesto)
½cupshredded Gruyere cheese
1tablespoongrated Parmigiano-Reggiano
freshly ground black pepperto taste
2teaspoonsmayonnaise
1tablespooneverything seasoning(optional)
extra-virgin olive oil,for drizzling
flaky sea salt,for garnish
fresh basil,for garnish
Instructions
Line a sheet pan with paper towels. Arrange tomatoes in a single layer and sprinkle lightly with salt. Let stand while prepping the rest of the recipe, turning after 15 minutes.
Place a baking sheet on rack of in upper third of oven. Preheat oven to 425°F.
Unfold the pastry on a piece of parchment paper. Roll it into a 10-inch square. (If your pastry comes in a disc, no biggie. Just make a round tart instead.) Lightly score a 1-inch border around all four sides, taking care not to cut through the pastry (it’s really just there for you to use as a guide when arranging the toppings). Spread center with mustard or pesto. Sprinkle with Gruyere. Pat the tomatoes dry, and arrangement them on top of the cheese. Sprinkle with Parmigiano-Reggiano and pepper. Brush edge of pastry with mayonnaise. If desired, sprinkle with everything seasoning. Use the parchment paper to transfer the tart (along with the paper) to the preheated baking sheet.
Bake 15-20 minutes or until the pastry is golden and puffed around the edges. Drizzle with olive oil, garnish with basil, and slice. Serve warm or at room temperature.