Coarsely grate the zucchini using a box grater.

Transfer the grated zucchini to a colander and sprinkle evenly with the 1 tablespoon salt.

Mix the salted zucchini and leave it to drain for 60 minutes.

Wrap the drained zucchini in a clean kitchen towel and squeeze out as much liquid as possible in 3 to 4 batches.

Preheat the oven to 180°C / 350°F with fan circulation.

Finely chop the onion, spring onion, parsley, dill, and mint.

Lightly beat the 5 eggs until the yolks and whites are combined.

Place the squeezed zucchini in the large mixing bowl and add the onion, spring onion, parsley, dill, and mint.

Add the flour, feta cheese, and half of the kefalotyri cheese to the zucchini mixture.

Pour in the beaten eggs and add the black pepper and dried oregano.

Mix the filling thoroughly until the ingredients are evenly distributed.

Grease the bottom of a 23 x 33 cm / 9 x 13 inch rectangular baking dish with a little olive oil.

Sprinkle half of the panko breadcrumbs over the oiled baking dish.

Pour the zucchini filling into the prepared baking dish and spread it into an even layer.

Sprinkle the remaining kefalotyri cheese over the filling, then cover with the remaining panko breadcrumbs.

Bake for 35 to 45 minutes until the pie is set in the center and golden brown on top.

Mince the garlic and finely chop the parsley and dill for the yogurt sauce.

Combine the strained Greek yogurt, 2 tablespoons olive oil, garlic, parsley, dill, salt, and black pepper in a small bowl.

Mix the yogurt sauce until smooth and evenly seasoned.

Rest the baked pie for 10 minutes, then cut it into 8 squares.

Serve each zucchini pie square with the yogurt sauce.