Press pastry dough into a 9-inch quiche dish with a rim height of 1 1/4-inches. Press the dough all the way up the sides, folding any overhanging dough in on itself.
Place dough-lined tart pan in the refrigerator to chill until firm, about 40 minutes. Transfer the tart pan to the freezer until very cold, about 20 minutes.
Meanwhile, cut the tops of the zucchini and courgettes. Use a mandoline to thinly slice them into long strips. Cut each strip in half down the middle (lengthwise). Place the strips in a colander set over a plate. Gently toss it with 1 teaspoon of salt and set aside for 30 minutes.
Place a clean kitchen cloth on the counter. Transfer zucchini slices to the towel and gently pat dry.
When the tart crust is almost done chilling, preheat your oven to 375° F. Remove the tart pan from the freezer and line it with parchment paper. Place pie weights on top of the foil. Bake for 20 to 25 minutes or until light golden in color. Transfer to a wire rack to cool. Keep oven on and finish preparing the filling.
In a bowl, prepare the cheese mixture. Combine the goat cheese, lemon zest, thyme, ¼ teaspoon salt and ¼ teaspoon freshly ground pepper. Spread cheese mixture in an even layer over cooled crust. If the mixture is too thick to spread, mix in 1 to 2 teaspoons of fresh lemon juice.
Layer zucchini and courgette slices on top of the cheese layer. Make sure the skin side is facing up (refer to photos as needed). Continue layering in concentric circles. Drizzle with a bit of olive oil and add a sprinkle of salt.
Bake tart at 375℉ for 25 to 30 minutes or until the crust is golden brown and the zucchini has darkened slightly. Cool for 10 minutes before slicing and serving.
Notes
Slice the squash into thin, long slices. If you don't have a mandoline, you can use a long sharp knife to cut the zucchini in half lengthwise, then put the flat side down on the cutting board before slicing into long thin strips. (be careful).Store covered in the refrigerator for up to 3 days. It's best when eaten the same day it's baked.Freeze for up to 3 months. After the tart has completely cooled, flash freeze it for an hour or until firm. Wrap the entire dish in plastic wrap and aluminum foil to prevent freezer burn. Defrost in the refrigerator before bringing to room temperature and serving.