Final answer:
Mushrooms and onions are commonly cooked at a temperature of around 375°F (190°C) if roasted, or until translucent or golden over medium to medium-high heat if sautéed. Using a thermometer ensures food reaches safe temperatures to kill bacteria.
Step-by-step explanation:
When cooking mushrooms and onions, the temperature can vary based on the cooking method. However, it's important to ensure that food reaches a high enough temperature to kill any potential bacteria. A safe guideline for cooking vegetables like mushrooms and onions would be around 375°F (190°C) if roasting in an oven. For sautéing on the stovetop, cooking until they are translucent or golden at a medium to medium-high heat is typical. It's also essential to use a thermometer for accuracy in certain cooking methods and to prevent failure of temperature control that could lead to bacterial growth.