Using a cast iron pan is one of the best ways to cook your food, but sometimes cleaning can be a major chore, especially if the pan has been "forgotten" and food is baked right on. To remove the "unremoveable," do this:
Sprinkle baking soda liberally all over the base of the pan. Fill the pan with about half an inch of water, and put onto the stove at a medium heat. As the water begins to boil the baking soda works away at cleaning the baked on food. Using a silicone spatula, gently push the food off the pan — don't worry about the sides, the steam will take it right off.
After cleaning, rinse the pan off and throughly dry it with a clean paper towel. Never use soap on your pan, or leave it wet or it will become rusty. Then just "season" the pan by rubbing a teaspoon of vegetable oil into the surface. Keep the pan seasoned by repeating the layer of oil after each cleaning and putting it into a hot over after something else has cooked and the oven has been turned off.