Spinach is boiled in salted water, drain and cut. Stir with the feta cheese, 1-2 tbsp butter, pepper and parsley to taste. Separately, boil the potatoes, grate in large pieces grater and add salt. In pan greased with butter spread half of the potatoes and pour 1-2 tbsp butter. On potatoes spread an even layer spinach and remaining potatoes on top and again pour 1-2 tbsp butter. Eggs are broken is milk, pour moussaka and bake until browned in a hot oven.