First off, anyone feel free to shoot me down on this.
When I look at this board, I see the power of Ambassador to neutralize the curse giving power of Young Witch. I also see the potential to build an engine around University/Minion. So I think I would actually open Potion/Ambassador. The goal here is to pick up University with $2P, use University to gain Minion, and then use the Minion cycling to play Ambassador as much as possible (maybe even pick up a second Ambassador if necessary). I want to stress this again, in the beginning of the game, I would *almost* always use Minion for the discard. The goal here is to bloat the opponents deck while increasing the power of your engine due to the University. At some point, I might also try to get some +buy from doubly activated Cities. Keep in mind that in this game, a 3-pile could be likely, so I would also want to make sure that my opponent didn't have a chance to steal a win from piling.