I vote for Authentic. “Good” is a Subjective Concept. What may taste good to one person might taste terrible to another. If a dish is consistently made the same way time after time then it becomes authentic over time regardless of how people interpret the tastes and flavors.
Eating Cooked Grubs in Cambodia may or may not taste good to someone who’s never eaten them before but if the Grubs were prepared the same way over and over for many years, that is the authentic way they are prepared regardless of how someone thinks they taste.