Me as a potions mistress?

Everything started on a stormy night at headquarters with a conversation which leads Hermione towards to the highest potions exam and they unnoticeably get closer and closer with the potions peerless master. AU, since Snape teaches potions in year 6 & there's no mention about the Prince's book. PS: This story is from the slow burn type, so don't expect smut in the 1 st chapters.