For most of us, childhood admonitions to "eat your vegetables" were heard all too often. Perhaps our reluctance to consume what should be delicious, naturally appealing food was prompted by plate after plate of vegetables overcooked to mush. We can’t necessarily fault the cook: boiling vegetables beyond recognition was the rule for previous generations, rather than the exception. Fortunately, today we know better.
Properly executed, moist-heat methods like boiling (and its variations, simmering and blanching) and the very gentle steaming are basic techniques that will cook vegetables, grains, and legumes to the desired doneness with flavour intact. Simmering is recommended in some recipes when softer or more delicate vegetables need gentle cooking; long-cooking dried beans and grains are always simmered. Blanching incorporates a brief dip in boiling water to loosen skin (tomatoes), to set color and remove rawness (vegetables for crudités), or to partially cook (vegetables for stir-frying). A microwave oven is also well suited to vegetables because it excels at moist-heat cooking and, along with steaming, minimises the loss of water-soluble nutrients.
When boiling vegetables, be sure to use a pot large enough to allow small pieces to tumble freely and large pieces to be completely immersed in the cooking liquid (which needn’t be limited to water; stocks infuse vegetables with delicious flavour). Steaming locks in nutrients and is a good choice for quick-cooking vegetables such as green beans, zucchini (courgettes), or summer (baby) squash. For steaming, some multipurpose pots have removable steamer inserts, a very useful investment if you enjoy steamed foods. One inexpensive option is a collapsible perforated steaming basket that sits inside a saucepan.
Test for doneness before the end of cooking time by probing one piece with the tip of a knife or by taking a bite. For the most even result, pieces cooked together should be of similar size, whether whole or cut up. When done, drain immediately to stop cooking.
Blanching
Bring a large quantity of water to a boil. Add vegetables -- here sugar snap peas -- and cook briefly. Just when the vegetables intensify in color and are barely crisp-tender (about 1 or 2 minutes) scoop from the water with a sieve.
Rinsing to Stop Cooking
As soon as the vegetables are blanched, rinse them under cold running water to stop the cooking and set their color. Toss, if necessary, so that all the vegetables come in contact with the water.
Boiling
Add water to a large pot and bring it to a rolling boil, then add vegetables (some recipes may ask you to place the vegetables in the pot first, then add water and heat). Reduce the heat to a slow simmer if specified.
Draining
As soon as the vegetables reach the desired stage of doneness, remove the pot from the heat and drain off the water by pouring the vegetables into a colander placed in the sink. Serve or use immediately, as the food will continue to cook from the retained heat.