Courgettes are cut into thin slices. Onions and garlic finely. Pour in a wide saucepan with a hot sunflower oil. Add zucchini and chopped spinach. Vegetables are steamed under cover about 5 minutes on low heat. In a large bowl whisk the eggs together with the spices. To these are added the grated cheese and steamed vegetables. Mix everything. Pour the mixture into a large round pan greased with the butter, and bake 25 minutes in the preheated oven temperature to 180 C. Fritatata must resembles a thin pancake.