What is a common method for cooking vegetables to retain their nutrients?

Steaming is recognized as a common method for cooking vegetables to retain their nutrients effectively. This technique involves cooking vegetables using steam generated by boiling water, which allows for a gentle cooking process without submerging the vegetables in water. Because the vegetables are not in contact with the boiling water, essential vitamins and minerals that can leach out during cooking are preserved to a greater extent.

Additionally, steaming helps maintain the vegetables' color, texture, and flavor, making them more appealing and nutritious. Other cooking methods, such as boiling, can lead to significant nutrient loss, particularly water-soluble vitamins. Roasting, while it can enhance flavor, typically involves higher temperatures and longer cooking times, which may also contribute to nutrient degradation. Frying introduces oils and high temperatures that can alter the nutritional content adversely. Therefore, steaming is the preferred method for nutrient retention among the options provided.