It doesn't matter how good a cook you are, everyone will burn food to the bottom of a pan at some point in their lifetime. Here's a few tips for cleaning off that horrible residue. Try using a fabric stain remover, just spray liberally and leave overnight before scrubbing. Or soak the pan with warm water and washing up liquid for a few hours then scrub, simmering gently for a while also helps. For really badly burnt pans try bi-carb soda or cream of tartar for each cup of water then leave for a few hours or overnight if the pan is not stainless. Then wash as usual. Never use bleach, steel wool, oven cleaners, and abrasive cleansers. And for non-stick pans, by cheap to begin with and just throw away.