The worst cooking mistake I ever made was when I tried to make cream of broccoli soup from scratch, shortly after I'd moved out of my parent's place for the first time. Since I didn't have a blender, I decided it would be a good idea to leave the soup on the "warm" setting of the stove overnight, sort of like a crock pot to soften it all up into mush. Bad. Idea. I woke up the next morning to find it had burned into a smokey black gel fused to the bottom of the pot. I spent three months soaking the pot in hot water to try to soften it up and scrape it out of there, and eventually just had to throw the cookware in the dumpster.