Frozen puff pastry makes this elegant and impressive savory tart easy to pull together. We use za’atar, a Middle Eastern herb, seed and spice blend, to add a perfect flavor accent to the sweet, summery tomatoes and zucchini. To keep these high-moisture vegetables from releasing water during cooking—and leaving the pastry soggy—we salt the slices for 20 minutes or so while the oven heats to draw out excess juices. The bonus is vegetables with more concentrated flavor that are nicely seasoned. As for the puff pastry, we prefer Dufour because it is made with butter and is of a size that needs only minimal rolling after the sheet is unfolded. Pepperidge Farm puff pastry works, too, though it lacks buttery richness. You will need only one sheet from the 17.3-ounce box (which contains two sheets), and it will need to be rolled out into a rectangle roughly 10 by 14 inches. Serve the tart warm or at room temperature.