Roaster ovens can bake, steam and roast as conventional ovens, but unlike their traditional counterparts, roaster ovens can be used as slow cookers. Most conventional ovens cannot maintain the temperature required for slow simmering, but roaster ovens range between 93.3 and 232 degrees Celsius. Converting a slow cooker recipe for use in a roaster oven requires little adaptation.
Examine the recipe for the temperature to preheat your roaster oven to see whether the dish should cook on high or low heat.
Set the roaster oven to 149 degrees C for a slow cooker recipe requiring the dish to cook on high heat. Preheat the roaster oven to 93.3 degrees C for low heat slow cooker recipes.
Decide if you need to cook the dish between 90 minutes and 6 hours or between 4 and 18 hours. Set your roaster oven to preheat to 149 degrees C for shorter slow cooking and set it to 93.3 degrees C for the longer cooking option.
Place the ingredients in the order according to the recipe into the cooking insert after a preheating of at least 20 minutes.
Convert a conventional oven recipe to use with the slow cooker function by looking at the cooking time of the original recipe and the temperature setting of the roaster oven.
Cook slow cooker recipes for the length of time required by the recipe. For instance, a recipe for chilli that requires it to simmer on low for 8 to 10 hours would cook in your roaster oven at 93.3 degrees C for 8 to 10 hours.
Use the temperature and original cooking time of conventional oven recipes to determine the length of time for slow cooking. Disregard the original oven temperature.
Convert conventional oven times of 15 to 30 minutes to use your roaster oven at 93.3 degrees C for 4 to 6 hours or at 149 degrees C for 90 minutes. Conventional cook times of 30 to 50 minutes require 6 to 10 hours at 93.3 degrees C or 3 to 4 hours at 149 degrees C. Oven cooking between 50 minutes and 3 hours you need to allow for 8 to 18 hours at 93.3 degrees C and 4 to 6 hours at 300 degrees.
Estimate all dishes with raw vegetables or meat will require at least 8 hours of cooking at 93.3 degrees C or 4 hours at 149 degrees C.