Heat a large pan over medium heat and melt the butter.
Add the thinly sliced potato to the pan, spreading them evenly. Cook until they start to become golden and crispy.
Flip the potato slices to cook the other side.
Add the chopped spinach on top of the potatoes. Season with black pepper and salt.
In a bowl, whisk the 3 eggs and pour them over the spinach and potatoes.
Sprinkle crumbled feta cheese on top.
Cover the pan and cook until the eggs are fully set.
