Learn Farsi: ما در مورد اینکه این خویشاوند دوردست اصالت ایرانی دارد بحث کردیم. - We discussed the fact that this distant relative has an Iranian origin.

The prepositional phrase در مورد (about) needs a noun as its object. You cannot attach a full descriptive sentence directly to a preposition in Farsi. By using اینکه (literally "this that" or "the fact that"), we turn the entire second half of the sentence into one large noun clause.

Do I need to pronounce an Ezafe before اینکه?

Yes, you pronounce it as dar moured-e اینکه. Multi-word prepositions like در مورد (regarding / about) always take an Ezafe to link to the noun that follows them. Even though the "noun" here is a whole clause introduced by اینکه, that Ezafe connection is still required.

In English, we just say "discussed the fact," but the Farsi sentence adds در مورد (about). Why?

The Farsi compound verb بحث کردن (to discuss) doesn't take a direct object like its English equivalent. Because it literally translates to "to do a discussion," you have to specify what the discussion was about by using a preposition like در مورد or درباره (about).

How does the phrase اصالت ایرانی دارد work to mean "has an Iranian origin"?

اصالت means "origin," "authenticity," or "roots," and it takes an Ezafe to link it to the adjective ایرانی (Iranian). Instead of saying someone "is originally Iranian" with the verb "to be", Farsi often uses the verb داشتن (to have) for characteristics, literally meaning the relative "has Iranian roots."}... wait, I need to complete the last sentence.