Cook Foods Insert the pan into the base of the roaster. Place the lid on the roaster and plug the unit into a power source. Turn the temperature knob on the front of the unit to the temperature you are planning to cook at. The roaster should preheat for 15 minutes.Click to see full answer. Also know, are you supposed to put water in a roaster?Adding water to the bottom of the roaster oven before cooking defeats the purpose of the unit, as its function is to roast, not steam, the food. During cooking, juices released by the bird or roast drip to the bottom of the cooking pan and are recycled as they travel up and around during the evaporation process.Likewise, how much water do you put in the bottom of an electric roaster? Fill the REMOVABLE ROASTING PAN from your Roaster Oven with 5 to 6 quarts full of water (or 1/2 – 3/4 full) and place inside ROASTER OVEN BODY. CAUTION: NEVER add water directly inside the ROASTER OVEN BODY. Moreover, how do you cook in a roaster? Here are the simple steps to keep your food warm with a roaster oven: Plugin your roaster oven and close the lid. Turn the temperature to 350°F and keep it on for half an hour. Turn down the heat to 200°F afterwards. Open the lid and put your warm food or buffet serves in the roaster oven. Can you use electric roaster pan in oven?The electric roaster has an electric heating element and a large, removable pan covered by a self-basting high domed lid when roasting turkey. Electric Roasters can be used to bake, roast and make soups and casseroles, as well as be used for keeping hot food warm, I love using mine anytime I can.