Mine usually starts with "How are you doing?" Sometimes she will ask "How was X thing?" if I had been talking about some event that was coming up. "How are you doing?" feels okay to me because that seems to invite talking about mood, sleep, what happened that week, how I feel about her/therapy, or anything else. I would not like a more specific question because I usually come in with an idea of what I want to talk about.

Have to asked your T specifically if he would do something different with you? I would find the blank stare thing a little awkward too.