+1 to what tradewater says. If you're in the food service business, you need to be providing SERVICE, not making judgments on other people's preferences. You cook what they want, and you deal with it if you think they're ruining the food. If you want to be able to judge them, you should be inviting them over to dinner at your house, where they eat what you cook and like it. If it's in a restaurant, the customer is always right. I'd have fired you in an instant if I ran that restaurant. I've been on the receiving end of shenanigans like that, all because the kitchen screwed my order up (ordered a triple, came with two burger patties instead of 3, asked POLITELY if I should have gotten a third, and ended up with nasty stuff in my burger). I did nothing wrong asking for the food to come as I ordered it, and frankly, I'd be surprised if this guy didn't order it well to begin with, in which case that was YOUR screwup, not his. Let's just say, in my case, it got up to a senior VP of the entire company, and the entire franchise was emptied out, and I was offered free food there for a year. That's how inappropriate that behavior is.