In a bowl, mix the flour and salt. Cut the cold butter into small cubes and add it to the flour mix. Using your hands, combine the ingredients coarse crumbs form.
Add the egg and 2 tablespoons of water to the mixture. Combine everything to form a dough. Wrap the dough in plastic wrap and refrigerate for 30 minutes.
Preheat oven to 350°F (180°C). Roll out the dough on a lightly floured surface and place it in the quiche dish. Prick the dough several times with a fork and pre-bake for 10 minutes.
Dice the zucchini. Heat the olive oil in a pan and sauté the chopped onion and minced garlic. Add the diced zucchini and spices. Cook for about 5 minutes.
In a bowl, whisk the eggs and sour cream together. Add the contents of the pan to the bowl. Season with salt and pepper to taste. Pour the filling into the pre-baked crust.
Sprinkle the shredded cheese over the quiche and bake for 30 minutes.