Restaurants draw the line on substitutions as diners push menu limits

Making substitutions at restaurants has become commonplace, but some chefs and restaurant owners are pushing back against requests they say can disrupt kitchen operations and take away from the intended dining experience.

The growing debate has also raised questions about restaurant etiquette, with experts warning that excessive modifications can cross the line from reasonable requests into entitlement.

Lom Wong, a Thai restaurant in Phoenix, Arizona, recently took a stance against...