Fast Food? How about Slow Food.
Johnny Knoxville working in fast-food as the elderly man character he does so well. He works slow, he drops food, picks it up, serves it to customer while customer witnesses. He falls asleep while in the middle of cleaning tables. He takes drive-through orders and can't get it right. He eats the food off of customer orders. Basically, the premise is to anger the customers.
Chris Pontius works in a sub-way style restaurant where people move down a line adding items to their order. His character does not know English but just nods like he does he understands. As people order, he does nothing right but keeps nodding and agreeing. Angers customers as he gets nothing right.