I steam mine either on the stove for about 2 minutes, or in a bowl, in the microwave, with a wet paper towl covering the bowl, and for about a minute or so
Actually, the best way is to make soup on a low simmer. Anything lost falls back into the general mish-mash.
Addendum: Make sure you don't let it boil. If you do you'll corrupt fatty vitamins like A and D.
The best way is to steem them until they get soft. Then u shouldn't loose that many vitemines
dont cooked it too well just enaf for the veges to soften
Steaming them till slightly tender.