This southern French tart takes its name from pissalat (or pissala), a pungent anchovy paste that gives the flatbread its distinctive flavor. Here, oil-packed anchovies are melted into the caramelized-onion topping.
- 1 package (¼ oz.) active dry yeast
- 3 cups all-purpose flour (15 oz.), plus more for dusting
- ¾ cup extra-virgin olive oil, plus more for greasing
- 1 Tbsp. kosher salt, plus more to taste
- 20 oil-cured anchovies, drained and finely chopped
- 12 medium yellow onions (5 lb.), thinly sliced lengthwise
- 4 sprigs thyme
- 2 sprigs rosemary
- 2 bay leaves
- Freshly ground black pepper, to taste
- ½ cup pitted, halved black olives
- Make the dough: Whisk together the yeast and 1 cup water, heated to 115°F, in a large bowl; set aside until foamy, about 10 minutes. Add the flour, ¼ cup oil, and salt; stir until a dough forms; transfer to a lightly floured work surface and knead until smooth, about 6 minutes. Transfer to a greased bowl, cover with plastic wrap, and set aside until doubled in size, about 1 hour.
- Meanwhile, make the topping: Heat the remaining ½ cup oil in a 6-quart saucepan over medium-low; add the anchovies and cook, stirring, until dissolved in the oil, about 7 minutes. Add the onions, thyme, rosemary, and bay leaves, season with salt and pepper, and cook, covered and stirring occasionally, until reduced and softened, about 1 hour; uncover and cook, stirring occasionally, until the liquid evaporates and the onions are golden brown, about 30 minutes. Remove from the heat and discard the herbs; let cool.
- Preheat the oven to 425°F. Uncover the dough and transfer to a lightly floured work surface; using a rolling pin, roll the dough into a 12-by-18-inch rectangle. Transfer to a greased 13-by-18-inch rimmed baking sheet, then cover evenly with the onion mixture; place the olives decoratively over the top. Loosely cover with plastic wrap and set aside until the dough is puffed, about 1 hour. Bake until the tart is golden brown at the edges, about 20 minutes. Let cool for 10 minutes before cutting into squares to serve.