Boil the potatoes, they must remain hard, peel, cool and grate them. Heat oil in a pan and fry the grated onions and leeks, add the grated carrot, chopped peppers and peas. Stir well and season to taste with spices.
Remove from the heat and mix with the grated zucchini, potatoes, and some more spices to taste, and finally - add the crumbled feta cheese. Whisk the eggs very well for awhile and mix them with the milk. Pour the vegetables into a form and pour on the egg sauce.
Cover the form with a lid and put it to bake at 356°F (180 °C) until set. Near the end, you can bake it uncovered.