Fresh and frozen vegetables can be cooked in a steam cooker. The key to preparing steamed vegetables properly is knowing how long to steam them so they are not under or overcooked.
When steaming vegetables, it is important to make sure they have been cut to a uniform size so they can steam evenly. Most steam cookers have a timer, which can aid in preventing vegetables from overcooking. Another factor to take into account is the density of the vegetable itself. Very dense vegetables like carrots and potatoes require longer cooking times than vegetables like broccoli or spinach. If more than one type of vegetable is steamed, then the denser vegetable can be placed in the steam cooker first, and the other vegetables can be added later.
Some popular vegetables to steam include potatoes, artichokes, broccoli, carrots and cauliflower. Vegetables can be seasoned while they are steaming with fresh herbs, spices, oils and prepared dressings. Although most vegetables can be cooked in a steam cooker, there are a few that are not recommended, such as bell peppers, mushrooms, garlic cloves and tomatoes. These foods are better prepared by roasting or sautéing so they can keep their structure and retain flavor.