Puff pastry, the flaky French dough, is available in sheets in the freezer section of most grocery stores. Choose a brand that is made with butter— ones made with vegetable shortening sorely lack flavor.
- Preheat the oven to 375°F.
- Line a large baking sheet with a piece of parchment paper and set aside.
- Roll the puff pastry out on a lightly floured surface into a 1/4 inch-thick rectangle the shape of the baking sheet.
- Transfer the sheet of puff pastry to the parchment paper–lined baking sheet.
- Using the tip of a paring knife, lightly score a border about 1/2 inch from the edge of the pastry. Prick the dough within the border all over with a fork to prevent it from puffing up too much during baking.
- Arrange the tomatoes on the pastry in a single layer (do not crowd or overlap the tomatoes or the puff pastry will be soggy).
- Arrange the olives on top of the tomatoes.
- Drizzle the tart with olive oil and season with pepper.
- Bake the tart until the pastry is crisp and deeply browned on the bottom and around the edges, 30–40 minutes.
- Remove from oven, season with salt, and serve.