Cast iron cookware. Though it takes a while to warm up, cast iron holds on to heat very well when it gets hot. It’s a good idea to warm a cast iron pan up for a few minutes before adding oil or butter. Before a cast iron pot or pan is used, it needs to be seasoned. Preheat the oven to 300 degrees F. Rub the pan all over with vegetable oil then put it in the oven for an hour. After that, wipe out residual oil with a paper towel. From then on, the pan shouldn’t be washed with dishwashing liquid, but should simply be rinsed with hot water and a scourer. It’s a good idea to season the pan now and then to keep it in good shape.