Why do it: Steaming has a nutritional advantage besides requiring no fat. "It retains among the highest amounts of nutrients of any cooking technique," nutrition specialist Wendy Bazilian, R.D., says. Steaming creates a closed environment that envelops the ingredients in moisture. It's the ideal technique for fish and vegetables, ingredients that tend to dry out easily. "Usually the paler and whiter the fish, the lower the fat," says Bazilian, who cites halibut, cod, snapper, and sole as examples. The trick is not to let the pan run dry. As a reminder of when to add more water, toss a few marbles or coins into the pan before you add the steamer. The force of the boiling water causes them to jangle; they'll quiet down when the pan dries out.
What you need: The standard steaming setup consists of a collapsible metal basket in a large saucepan with a tight-fitting lid. For a makeshift version, place a small heatproof bowl upside down in a deep pot, add ½ inch of water, and balance a small heatproof plate on top. Place the food on the plate, then cover the pot with its lid. If you steam often and in large amounts, consider a bamboo steamer; its large, stackable trays allow you to steam fish on one layer, vegetables on another.
Tip: Drizzling a few drops of olive oil over steamed food just before serving will impart far more flavor than sautéing the ingredients in an entire tablespoon of fat.