I forgot to mention, for this opportunity to show up you must have in the town your sim lives in the rabbit holes that came with Supernatural. I know that if I have a sim who completes their alchemy skills and lives in a town that does have those location in their town the opportunity doesn't arises.
http://vignette2.wikia.nocookie.net/sims/images/0/0c/Fae_Ray_Arboretum.jpg/revision/latest/scale-to-width-down/185?cb=20120918083957&format=webp
http://farm9.staticflickr.com/8168/7516755582_6840f2b1d6.jpg
Not the lager stuff, just the rabbit holes.