How long do you cook something 275 if the recipe calls for 400?

It is not possible to provide a precise conversion time without more context. Cooking time can vary significantly based on the specific dish, the ingredients, and the cooking method used. Additionally, adjusting cooking times between different temperatures requires considering various factors such as the properties of the food and the heat transfer rate at different temperatures.

In general, cooking at a lower temperature for a longer duration can help preserve moisture and prevent overcooking. However, the specific time adjustment will depend on the particular recipe and the desired outcome. It may be helpful to refer to cooking guides or consult with a culinary expert for more accurate guidance.