Pulling epoched data from specific vertices

Hi MNE users,

I have 40 ROIs with which I am trying to run a single-trial granger
causation analysis on. Instead of pulling all of the data from each
ROI, I am hoping to find a command that will return the vertices list
within an ROI. Is there such a command? In addition, is there a
command that will return the epoched data from a vertices list after
specifying the condition? Originally I was using
mne_compute_raw_inverse specifying an ROI and then mne_epochs2mat to
pull the data. But, it will be much more efficient if I can just input
the vertices that I need. Thanks in advance.

Best,
Corey