Whole grains are not that hard to prepare and can even be cooked in a slow cooker. In fact, cooking most grains is very similar to cooking rice. You can start by putting the dry grains in a pan of water or broth and bring it to a boil. The next step is to simmer until the liquid is absorbed and turn off the heat. But grains can vary in cooking times based on their variety, age, as well as the pan used for cooking.