creative writing - How to write about what you don't know?

I am a strong believer in writing what you know. Everything I write is at least partially based on something that I have experienced.

My problem is that for plot reasons, I need one of my characters to grow up in a culture and environment I am not familiar with. I need at least a chapter in that area. My goal is to portray the culture and belief of that region as a native.

I thought about reading books located in that area and maybe speaking with natives. However, it is in a region that is not portrayed in movies and seldom in books. Yet enough of my potential readers are familiar enough with the area to spot made-up things.

Are there any methods to facilitate simulating an empirical knowledge of a relatively unknown area?

N.B. this is not a duplicate of Writing about a subject on which you have no expertise?, which is about technical writing.

I found a partial answer in How to do research to write characters from a different culture?