[header] How to make duchess potatoes [title] Preheat the oven. [step] The final step in preparing duchess potatoes is baking them in the oven. To ensure that the oven is hot enough when the potatoes are ready, it's important to preheat it. 
Set the temperature to 400 degrees fahrenheit (200 degrees celsius), and allow it to fully heat. [substeps] Your oven will alert you that the oven has preheated in some way.