@Pedroli, here is the thread you are looking for
First, you need to find a university that wants to hire you. @tatterdemalion used to post jobs for English teachers here but not for a few months (thanks for your service).
The MOST has a job site that focuses on professors in the sciences, but there are others from time to time. I applied for a few Taiwan uni jobs that were advertised on various international job boards (I don’t have the links any more, but THE and the Chronicle are two that come to mind).
Getting a job depends on what your PhD is in, and a lot of other factors. It is very competitive now because the number of students is dropping, so there are fewer and fewer jobs available. If you are in a competitive field and have a competitive CV, that is good. If your PhD is in something obscure with little relevance to Taiwan/Taiwanese, and you don’t have a solid background in teaching and research, then getting a uni job will itself be a full time job for a while.
Once you find someone that wants to hire you, they will take you through the hiring process. For the MOE, the hiring process includes getting your degree authenticated, which is a bit inconvenient and I’m pretty sure this has been discussed in this thread.