Either the interviewer or the committee members usually begins by asking simple questions about your background.
Is this the correct way to use this sentance for subject verb agreement?
With an "or," make the verb agree with the noun in the subject that comes closest to the verb. In your case, "the committee members" is plural so you would use "begin." But unless they all begin at the same time, you may want to say "one of the committee members" -- and in that case, you would be back to the singular.
[not a teacher]