There's a ready a cast iron Dutch oven has been a popular product in the kitchen for decades. That's because cast iron is an excellent heat conductor and very durable in use. It takes a while for a cast iron Dutch oven to heat up, but once the pan is hot it retains the heat well. As a result, cooking in a cast iron Dutch oven is energy-efficient. In addition, the heat gets distributed over the entire pan. Cast iron is a sturdy material that retains it's form, but it's also relatively heavy.