Grease a 8 x 8  inch baking pan with olive oil. Preheat the oven to 350 degrees.

Place 3 tablespoons of olive oil into a large pan over medium heat. Once the oil is hot, add the zucchini into the pan and cook, stirring occasionally until it softens and the water from the zucchini has evaporated, about 10 minutes. Transfer from the heat and cool to room temperature.

Add the crumbled feta, parsley, eggs, pepper and zucchini into a large mixing bowl. Mix well until everything is distributed evenly.

Place the empty baking pan into the oven to heat up for 5-10 minutes. Carefully transfer from the oven and immediately add the zucchini mixture. Spread the mixture  in an even layer and bake it in the oven until it is set and golden brown on top, about 50 minutes. 

Serve hot.