Wash mustard greens thoroughly by dunking them several times in a bowl of water and then rinsing in a colander. Then chop or tear into bite-sized pieces. Because of their sharp flavor, mustard greens should be combined with other greens.
Cook until tender but not mushy, about 10 to 15 minutes.
To decrease the bitter flavor of mustard greens, cook them in boiling water for one minute before sautéing. Then sauté in oil until tender, about 15 minutes.
Place mustard greens, just with the water clinging to their leaves, in a covered microwave-safe casserole and cook on high for 7 to 10 minutes, until tender. Stir after 4 minutes. Let stand for 3 minutes before serving.
Temper the strong flavor of mustard greens by cooking them with more mild-tasting greens, such as chard or spinach. They also combine well with sweet-flavored vegetables, such as sweet potatoes, corn, or carrots. Chopped mustard greens can also be added to soups or stews to add a pleasant, peppery aspect to these dishes. They are especially good with bean soups. Flavors that go well with mustard greens include vinegar, hot pepper sauces, garlic, chile peppers, and lemon.