Best 15-30 minute Army class to teach?

Just got a random text from my sqaud leader that every soldier needs to be prepared sometime this week to teach a 15-30 minute class on any army topic. We can teach it however we want as long as it is professional and actually structured. Any ideas for something good to do? I don’t want to do the basics such as land nav or ppw stuff. Genuinely want a unique, underdeveloped skill/knowledge to teach.