No. You can't charge staff for broken (burned) equipment or product according to federal labor guidelines. It's not ethical either.
No offense, but what you have is not a staff issue, it's a training and/or management issue. You either haven't trained your staff properly, haven't taught them your standards, or aren't managing them properly. If there is a manager on duty at night, they should be responsible for quality control. If there isn't anyone in charge, then you have a rudderless ship that is bound to crash into some reefs, and no accountability.
There is an easy fix to this problem. Put someone in charge of that shift. Teach them how to properly heat up meatballs. Instill your standards for quality in them. Hold them accountable when they screw up by reprimanding them. Replace them if they can't fix the problem. I apologize for being so blunt.
