tool basics, Steamed Cod with Crisp Vegetables
From stainless steel to bamboo, there are almost as many kinds of steamers as there are things to cook in them. A pasta pot fitted with a deep, perforated basket can steam almost anything. There's room for only about an inch of water, though, so these pots are best for foods that cook in less than 30 minutes. Shallow steamer baskets hold less, but they allow more room for water, so you can use them for foods that cook more slowly; you can also boil some ingredients and steam others at the same time. Foldable steamer baskets are inexpensive and can fit any pot; bamboo steamers that fit over woks don't cost much, but boiling water in a wok can ruin its seasoning. Stacked oval metal steamers are more expensive, but they're the most versatile—they can hold everything from fish to Cornish hens.
Steaming in Foil
The easiest, most delicious way to steam food is to cook it in foil. Here, a few flavoring tricks.
Add chopped herbs, thinly sliced garlic, onions or tomatoes, which will steam while your main ingredient does; precook hard vegetables such as carrots before adding them to the pouch.
Drizzle olive oil or add a teaspoon of butter to lend a lot of flavor and only a little fat.
Splash on wine or citrus juice; it will combine with any liquid the foods give off to make a simple and tasty sauce.
One health benefit of steaming is obvious: You don't need to add any fat to prevent food from sticking to the pan and burning. Steaming is also one of the best techniques for preserving vitamins B and C in food. These water-soluble vitamins are destroyed by slow-cooking methods like braising and get washed away by boiling. A recent study in the Journal of the Science of Food and Agriculture found that steaming is the best way to preserve flavonoids— compounds that may help protect against disease.