If your only acquaintances with radishes are the red and white circles that lurk next to the tomatoes and cucumbers in your green salad, you'll be surprised to learn that radishes can be a tasty addition to your skillet or roasting pan. Radishes are rich in folic acid, potassium and vitamin C and the available types range from the ubiquitous red globe radish to the peppery hot black radish to the carrot-shaped daikon radish popular in Japanese cooking. Radishes are best cooked using methods similar to those used for their close relative, the turnip. They can be braised, sauteed, roasted, steamed or boiled.
Braising -- cooking over low heat in a covered pan -- yields flavorful radishes that are crispy-tender, but not mushy. To braise radishes, remove any attached greens and peel if you like, although the only type of radish that must be peeled before cooking are black radishes. Heat butter and oil in a large skillet, add the radishes and pour in liquid -- preferably any type of chicken, beef or vegetable stock or even white wine -- seasoned with vinegar, sugar, salt and pepper.
Bring the mixture to a simmer, turn the heat to low, cover the skillet and allow to cook until the radishes are tender, approximately five minutes. Remove the lid and cook the radishes over medium-high heat until the liquid has become thick and syrupy and coats the radishes.
Radishes can be diced, minced, sliced into thin rods or grated and sauteed either alone or with a variety of other vegetables in stir-fries. Black radishes and daikon radishes are the types most commonly used in sautes. Both take well to the spicy, pungent flavors common in Asian-inspired saute dishes, but if you'd like to tone down their acidic bite, peel the radishes and thoroughly salt and wash them before using.
Like other root vegetables, radishes can be roasted under high heat with minimum seasonings and preparation time. Toss sliced, cubed or whole radishes with olive oil, salt, pepper and any other desired seasonings and place on a rimmed, oiled baking sheet on the center rack of an oven preheated to 425 degrees. Roast the radishes for 30 to 45 minutes, using a spatula to turn and stir the radishes halfway through the cooking time, until they are fork-tender and browned.
If you'd like to roast radishes with other produce, choose vegetables with a texture similar to radishes -- turnips, carrots, parsnips, potatoes -- to ensure that all require the same cooking time.
Steam radishes whole by putting them in a steamer placed over 1 to 2 inches of boiling water, then covering the pan and leaving undisturbed for five to 15 minutes, depending on the size of the radishes you use. Steamed radishes are an excellent addition to fruit and vegetable trays and salads and can be added to soups, stews and other dishes.
Whole or sliced radishes can be cooked in boiling water for 10 to 30 minutes until tender and cooled and then eaten warm or after chilling. After boiling, half-inch thick slices or quarters of any type of radish can be grilled until brown, drizzled with a vinaigrette and used as an unusual side dish or added to salads.