I know it sounds odd, all directions tell you to preheat your oven. But unless you are making bread or some other tricky baked good, you probably don’t have to preheat your oven, especially with meats. Just put the dish in and cook it like you normally would, turning the oven on as you put in your dish. And unless you have to touch the dish or put a thermometer in it to test the temperature, just look through the oven door to make sure it isn’t burning instead of opening the oven door. It will help keep the heat in so your oven doesn’t have to work as hard to keep itself hot.