We had an annoying vegetarian customer that found out about the grease so he'd request his fries cooked in a different vat, frequently I did it in the fish vat. There was another one that always ordered his burgers without pickles and he'd get upity if he thought we'd taken a regular burger and removed the pickles (which was frequent, also very detectable on a cheeseburger), I'd pour some pickle juice on his bun. Dribbling the ketchup around the outside of the bun rather than globbing it in the middle had the same effect as not busting the yoke in a mcmuffin. What was a blow burger?
Back in the day when the burgers were grilled, you'd put those nasty reconstituted onions on the regular burgers while they were being cooked. If someone wanted a burger w/o onions you'd pick it up on the spatula and blow the onions off.