According to markiplier, it is the henchman to a kitchen Hitler. Similar to how Hitler had henchmen to do his dirty work, a kitchenheimer would do all of the dirty work for the head chef of a restaurant.
"Man, I hate being my boss's kitchenheimer. Just because he doesn't want to do the shit-work around the kitchen since he's the head chef doesn't mean that I WANT TO do it."
I was in the kitchen this morning walking around in circles wondering what the hell I was looking for when the microwave beeped reminding me I was heating up my cup of coffee. My Kitchenheimer's is getting worse!
A sous chef to a kitchen Hitler , cause Oppenheimer was one of Hitler's henchmen . "And there for a (Kitchenheimer) would be the subordinate to a kitchen Hitler . So he aid's in his crusade against everyone in his kitchen