Serves 4

PASTRY

1¼ cups flour

¼ teaspoon salt

¼ teaspoon baking powder

1 tablespoon sugar

6 tablespoons unsalted butter, cut up

1 egg

1 teaspoon distilled white vinegar

1 tablespoon ice water, or more if needed

Extra flour (for sprinkling)

1. In a food processor, combine the flour, salt, baking powder, and sugar. Pulse to blend them. Add the butter and pulse again until it forms small crumbs.

2. In a bowl, whisk the egg, vinegar, and 1 tablespoon ice water. Pour the liquids onto the flour mixture and pulse just until it forms moist clumps. The dough should not come together in a ball. Add more water, 1 teaspoon at a time, if necessary, until the dough forms clumps.

3. Turn the clumps out onto a lightly floured counter and use a bench scraper or palette knife to cut through the mixture again and again until it almost comes together. Using floured hands, knead for 1 minute, or until it forms a smooth dough. Flatten the dough into a disk. Wrap in foil and refrigerate for 15 minutes.

4. Set the oven at 400 degrees. Line an unrimmed baking sheet with parchment paper.

5. Lightly flour the middle of the paper. Set the dough on it and, using a floured rolling pin, roll the dough, turning the paper several times, and adding more flour to the pin as necessary until the dough is very thin and about 10 inches across.

6. Fold over the edge of the dough, making a ½-inch hem. Use a fork dipped often in flour and press the tines around the edge. Refrigerate for 5 minutes.

TOPPING

1 cup freshly grated Parmesan

¼ cup panko, or other plain white breadcrumbs

1 tablespoon Dijon mustard

3 medium tomatoes, cored

Olive oil (for sprinkling)

Salt, to taste

Small handful fresh basil leaves, torn up

1. In a bowl, combine ½ cup of the Parmesan, panko or breadcrumbs, and mustard. Stir them with a spoon to make a crumby mixture. Spread the crumbs on center of the pastry, not on the rim.

2. Halve the tomatoes horizontally. Hold a tomato half over a bowl and, using a finger, remove the seeds. Cut each tomato into ¼-inch slices. Lay the slices on the tart. Sprinkle with the remaining ½ cup Parmesan.

3. Bake the tart for 25 to 30 minutes, or until the cheese on top browns and the edges of the pastry are golden.

4. Sprinkle the tart with olive oil, salt, and basil. Cut into wedges. Sheryl Julian

Sheryl Julian can be reached at sheryl.julian@globe.com. Follow her on Twitter @sheryljulian.