How to Make It
In a food processor, pulse the flour with salt. Add the butter and pulse until the mixture resembles coarse meal. Add the eggs and pulse until the dough looks like wet sand. Transfer the dough to a work surface and pack it into a ball. Using the palm of your hand, flatten into a disk, wrap in plastic and refrigerate until chilled, about 2 hours.
Preheat the oven to 375°. On a lightly floured work surface, roll out the dough to a 13-by-16-inch rectangle about 1/4 inch thick. Fold the dough in half and, using 2 large spatulas, transfer the dough to a large baking sheet, then unfold it. Refrigerate the dough until firm, about 15 minutes.
Fold up the edges of the dough to make a 12-by-15-inch rectangle. Scatter the garlic, onion and zucchini on the dough and season with salt and pepper. Arrange the tomato slices in slightly overlapping rows inside the rim of dough. Fill in any gaps with the cherry tomatoes. Season with the herbes de Provence and salt and pepper. Decorate with the anchovy fillets. Sprinkle the Parmesan over the tart and drizzle with olive oil.
Bake in the upper third of the oven for 30 minutes. Move the baking sheet to the lowest oven rack and bake for 25 to 30 minutes longer, or until the crust is crisp and browned and the cheese is lightly browned. Let the pissaladière cool for about 5 minutes, then cut into 4-inch squares. Serve the tomato tart warm or at room temperature.