Nitrients in food
That said, I cam across an interesting article about cooking methods and nutrient retention in broccoli. (It wouldn't be too much of a leap to assume that the same goes for other vegetables as well.) The bottom line is that stir frying is perhaps the best method for locking nutrition in the broccoli. With microwaving, you lose nutrients, mostly vitamin C because it leaches out with any water you cook. I assume that steaming and boiling vegetables does the same thing. That's why the water has that green color when you are done! I suppose you could drink that water or put it into soups instead of pouring it down the drain. And one last thing, stir fry with heat resistant oils like extra virgin olive oil, coconut oil or lard. Some of the other oils don't lock in the nutrients as well and the high heat chemically changes most vegetable oils into toxic compounds.