The simplest way to cook spinach is in a pan with a little olive oil and butter, a pinch of nutmeg and a small stream of lemon juice; put a lid on and let it cook in the steam. It will taste good, and it will go with almost anything: pasta, fish or meat. If there is excess moisture when the spinach is cooked, simply tilt the pan so that the liquid goes to one side and remove it. Let the spinach rest for a minute and serve.