My wife heard this term on TMZ today and it means marijuana. ┬áThere is a rap song by D.R.A.M and Lil Yachty called Broccoli and it’s about marijuana.

There was also a song by the rapper E-40 where he coined the phrase back in the early 2000’s.

http://www.hotnewhiphop.com/dram-broccoli-feat-lil-yachty-new-song.1969278.html