I have an idea: I'd write only an English title tag and an article in
another language. For the English page, I'd use the English title but
all other content would be identical to the other language page. That
would be an efficient way to get traffic from foreign counties.
Let me consider the following example.
Someone created a web page with an article in Mongolian, but the name of the article was created in Arabic. Arabic-speaking user (not learning Mongolian) can see in the SERP title of the article and would pass on this web page. I doubt that this user could read the article in Mongolian. A Mongol-speaking user (who has not studied Arabic) would simply skip this article in the SIRP, which has a name in Arabic. Thus, this article is unlikely to attract high traffic, especially the traffic of targeted users who are looking for the subject of this article. When creating an article, this bilingualism may be deemed irrelevant or even misleading, as it could be with an Arabic-speaking user.
This also contradicts the following Google recommendation of Managing multi-regional and multilingual sites:
Make sure the page language is obvious
Your idea probably doesn't make sense.