Kiss their boots

I have just read this.

It's not a new or novel idea for a restaurant to let you pay what you think a meal is worth, I think you'll find it's actually enshrined somewhere in the law of the realm. There is nothing to stop you eating in one of Gordon's Dorchester posh troughs and bunging the maître d' a fiver if that's what you think the meal is worth. If it's crap and the service is awful you can be assured the full magnificence of the law and the magnanimity of justice will be right behind you as you argue the toss. Good luck.