The traditional way to cook spinach is to dump the washed spinach in a cook pot bit by bit, and let it shrink over high heat. When done, it was chopped to pulp with an axe and served with a creamy sauce.
I prefer to stir fry a chopped onion in olive oil, and when soft and translucent to add the (chopped) spinach bit by bit and stir until done. Adding crème fraîche is optional.
Delicious with new potatoes, served with a knob of butter, and a hard boiled egg.