We've seen spinach move from most-despised vegetable to trendy beyond belief (remember spinach salad?) to something that appears to be taken for granted. It deserves none of these states of being. Rather, it's a green that is best cooked -- and cooked well -- and one that has few equals.
It's also among the first greens to appear locally in spring, before the weather becomes too hot to grow it. I know that everything is year-round now, but I'm talking about real spinach from real farmers -- not the stuff in cellophane (which isn't bad, after all), but the tender, flat-leaved variety that's sold by the pound. Sometimes this has thin enough stems so that it barely needs trimming. It cooks lightning-fast, in water, oil, or butter.
The oxalic acid in which spinach is high (rhubarb has it too, and chard, and beet leaves) is what gives it the astringent flavor that was once so reviled. Now, I think we appreciate that unusual flavor more, but we've also recognized that complementing spinach with fat - bacon and butter are perhaps best, but good oil is lovely, and there are cheesy ways that work well also - is perhaps the best way to enjoy it. This is nothing new: I've found old recipes in which spinach is cooked for hours and hours, with butter added every now and then, until the dish is perhaps best described as spinach-scented butter.
But you don't need gobs of fat to make spinach delicious: I'm not sure there's a more pleasant way to treat it than the cold (but cooked) Japanese sushi-style version, which is nearly fat-free (though a sprinkling of sesame oil doesn't hurt). And there's not much oil in the classic spinach with raisins and pine nuts (garlic is good in there, too, as it is in many spinach dishes), which in Provence they take one step further and make into a sweet pie.
It's easy enough to buy good spinach: the leaves should be dull or bright green, but not at all slimy; simple enough. If the stems are thick, pinch or chop off the ends, and cook it a little longer, or until they're tender; if they're thin, do nothing. You must wash it well, of course, and with real, fresh spinach, which can be quite sandy, this is exceptionally important: There is nothing worse than gritty spinach (and in a restaurant there is no excuse whatsoever), so if you have to wash it five times, do so -- it'll take three minutes, tops.
The cooking style is entirely up to you: Some people favor steaming, which is unquestionably fast (you can steam it with just the water that clings to the leaves after washing), but I prefer these three basic methods. One, dump it in a full pot of boiling salted water and cook it until it's done, just a minute or at most two; I don't know why, but I think this results in better-looking, better-tasting spinach than steamed. Two, throw it in a heated and oiled pan and flash cook it -- it'll wilt in a minute. (It's best if you roughly chop it first.) Or three, cook it slowly (again, chopped first is better), with oil or butter and whatever else you like, until it's really really tender. Which isn't long -- ten or fifteen minutes.
Having done any of those things, you don't need recipes (though the ones here are useful and lovely, of course): top cooked spinach with a little butter, lemon juice, vinegar, nutmeg, really good olive oil, or cream. Or try soy sauce, vinaigrette, Parmesan, bread crumbs, or sesame oil.