Why cook vegetables – aren’t they better for you raw? The best reason: often they taste better and in some cases cooking unlocks nutrients so that your body can better use them. Here’s a rundown of popular cooking methods for vegetables.
Dry vs. Moist Heat
Cooking methods are classified as either dry or moist depending ‐ not surprisingly ‐ on whether they involve water. Dry‐heat cooking methods include baking, roasting, deep‐fat frying, sautéing, and stir‐frying. Moist‐heat cooking methods include boiling, simmering, steaming, and slow cooking.
Baking and Roasting
In baking, the food is cooked by surrounding it with heat ‐ in either a conventional or convection oven. Baking tends to brown the outside of foods and seal in moisture, and is therefore a good method for cooking potatoes and winter squash. A convection oven circulates the hot air using a fan, which cooks foods more evenly. Also, foods usually cook about 25 to 30 percent quicker in a convection oven, saving time as well as using less electricity. To convert a recipe for a conventional oven to a convection oven, reduce the heat by 15 degrees C (25 degrees F) and cook for less time.
Vegetables can also be baked along with a Sunday roast or in casseroles or baked pasta dishes. Sneak more vegetables in your diet by incorporating them into baked goods such as carrot cake, courgette bread, pumpkin muffins, or sweet potato pie.
What’s the difference between baking and roasting? Roasting used to mean cooking over an open fire. Today it basically means the same thing as baking. Some use baking to refer to cooking baked goods that contain flour, such as breads and cakes, and roasting to refer to cooking meats and vegetables. What used to be called roasting is now more commonly called grilling or barbequing.
The most popular deep‐fried vegetable is the potato – in the form of chips or crisps. Vegetable tempura ‐ vegetables dipped in batter and deep‐fried – is another great way to enjoy vegetables. Asparagus, aubergines, broccoli, carrots, cauliflower, courgettes, onions, peppers, potatoes, squash, string beans, and sweet potatoes all make good tempura.
In sautéing, foods are cooked quickly in a sauté pan or skillet using high heat and a small amount of fat. What’s the difference between sautéing and pan frying? In sautéing, the pan is shaken so that the food “jumps” – the French verb “sauter” actually means “to leap”. In pan frying, the food is cooked at a lower heat and usually turned once with a spatula. Many vegetables are good sautéed in a little olive or canola oil (alone or in combination), including courgettes, yellow summer squash, spaghetti squash, leafy greens, onions, garlic, peppers, snow peas, string beans, broccoli, and carrots. Dense vegetables such as broccoli or carrots may be sliced thin, julienned, or steamed first to cut down on cooking time.
In stir‐frying, food is cooking over very high heat, usually using a wok, although you can use a skillet. Stir‐frying is a very healthy cooking method: it cooks quickly without water (which retains vitamins) and uses very little oil. Vegetables are cut into small pieces and added to a preheated wok containing a small amount of oil. The vegetables must be stirred constantly to ensure even cooking and prevent burning. The key to proper stir‐frying is organisation: have everything chopped and ready to go. With gas stoves, a wok with either a round or flat bottom can be used. Round‐bottomed woks are set in a ring that keeps them stable. On an electric stovetop, either a flat‐bottomed wok or a skillet is used. Heat the empty wok first; once the wok is hot add a little oil, rotating the pan to coat the surface. Good vegetables for stir‐frying include broccoli, carrots, onions, peppers, garlic, peas, cabbage, string beans, cauliflower, and leafy brassicas.
Boiling and Simmering
What’s the difference between boiling and simmering? Water boils at a temperature of about 100°C (212°F). When water reaches a rolling boil it contains big bubbles that break, creating a great deal of motion. In simmering, the water contains small bubbles that break on the surface, with just a little motion. Water simmers at about 60° to 85°C (140° to 185° F). Vegetables that are often boiled include potatoes, cabbage, root vegetables, and onions. Many nutrients are boiled away into the water, so try to save the liquid and add to soups and stews. Soups, stews, and dried bean dishes are simmered, not boiled, and since the liquid is consumed as part of the dish, nutrients are not lost.
Steaming is one of the easiest and most nutritious ways to cook vegetables. In steaming, vegetables are cooked gently over – not in – hot water. Vegetables are put in a perforated steaming basket which is then placed in a pot containing 1.5 to 3 cm (1 to 1.5 inches) of water. Water should be below the level of the steaming basket, so that nutrients aren’t leached away into the water. You can use a pot especially designed for steaming, but you don’t really need one. Steaming is done over medium heat. Be careful not to let all the water cook away. Almost any vegetable can be steamed, including asparagus, spinach, summer squash, courgettes (zucchini), peas, broccoli, sweet corn, string beans, Brussels sprouts, cauliflower, Swiss chard, kale, cabbage, beetroot, onions, potatoes, turnips, turnip greens, mustard greens and sweet potatoes. Dense vegetables should be cut into small pieces to cook more quickly.
These are just a few ways to cook your favourite vegetables. For information on microwaving and slow cooking see “Slow Cooking and Microwaving Vegetables“. Experiment and try different methods: getting more vegetables into your diet is one of the best ways to improve your health!