In the meantime, mix the ricotta cheese, mozzarella cheese, Parmesan cheese and basil. In a small bowl, whisk the olive oil and the garlic together and add 1 teaspoon of the garlicky olive oil to the bowl with the cheeses and season with salt and pepper to taste and mix well.
Cut zucchini into thin slices and place over paper towels, sprinkle some salt over the slices and let sit for 30 min so the paper towels soak up all the water.
Start by making the pastry dough. Add the flour and salt to a large bowl and slightly whisk. Cut the butter in pieces and add to the bowl. Using a pastry blender or two knives cut but butter in until the mixture resembles coarse meal. In a small bowl, whisk together the sour cream, lemon juice and water and add this to the butter-flour mixture. Using a wooden spoon or your fingers, mix in the liquid until large lumps form. Pat the lumps into a ball; do not overwork the dough. Cover with plastic wrap and refrigerate for 1 hour.