Given the dangerous surroundings, the kitchen is off-limits to patrons. It simply isn’t safe. Professional cooks handling sharp knives shouldn’t be distracted by diners’ inquiries. You also wouldn’t want patrons entering the kitchen to dip their fingers into a sauce to see whether they want to order an entree or not. To prevent these intrusions, most restaurants have a closed door that separates the kitchen from the area where diners are served.