Business in this hotel has been bad recently. The boss said there was something wrong with the chef's food, and the guests reacted. Should I quit my job as a chef? What should I tell the boss?

Now that the boss has said that it is the chef's dish, it means that he is implying that your hotel can no longer operate. I hope you will resign voluntarily, instead of letting him fire you. At this time, you have to think about it. If you really don't need to do it, then you should resign decisively and find another hotel job.