Dough

1. In a medium bowl, combine the flour and salt.
2. Add the butter, and using your hands, work it into the flour until the mixture resembles coarse meal [the butter pieces should be about the size of large peas].
3. Add the water and mix until the dough just comes together.
4. Flatten into a disc, wrap in plastic wrap, and chill in the refrigerator for at least 1 hour before using.

Filling

1. After the dough has chilled for at least an hour, preheat the oven to 400 degrees F. On a floured surface, roll out the dough into an 11-inch x 15-inch rectangle (approximately). Roll the dough around the rolling pin and unroll onto a baker’s quarter sheet pan (9-inch x 13-inch) so that the dough is falling over the edges on all sides. If you don’t have a quarter sheet pan, you can use a half sheet and use a folded up piece of aluminum foil to create a false side in the middle of the long edge so that the pan measures 9-inches x 13-inches. Trim the overhanging excess dough, so that the crust reaches just to the top of the edges of the pan [see note below for a fun use for the excess dough]. Cover the pan lightly in plastic wrap and transfer to the refrigerator to chill.
2. While the dough chills, prepare the ricotta mixture: in a medium bowl add the ricotta, egg white [reserve the yolk for the egg wash later on], oregano, thyme, garlic, salt, and freshly ground black pepper. Mix to thoroughly combine.
3. Remove the chilled prepared dough from the refrigerator and remove the plastic wrap. Spoon the ricotta mixture into the middle of the tart and use a spatula to spread it evenly over the bottom. Arrange the tomato slices over top of the ricotta and garnish the tart with more oregano leaves and flaked or coarse salt.
4. In a ramekin or small bowl, beat together the reserved egg yolk and splash of milk. Using a pastry brush, brush the egg wash over the exposed parts of the crust.
5. Transfer the tart to the preheated oven and bake for 45 – 50 minutes, until the crust is golden brown. Remove from the oven and transfer to a wire rack to cool for at least 15 minutes before cutting into squares to serve. [The tart is delicious served either warm or at room temperature, garnished with more fresh oregano and thyme leaves].