Moto E (1st Gen) failed to root

[Andy McG]

Device:
Moto E (1st Gen) XT1021

Computer:
iMac (late 2013) OS X 10.11

Problem: :
The phone gets stuck on "Warning Bootloader Unlocked" screen then goes to Android bot laying on it's back with red exclamation mark over it and the words "No command".

Steps taken:

• I've successfully unlocked the bootloader via Motorola's official pages.

• I have Android SDK studio loaded in the right place on my mac /Users/username/Library/Android/sdk/

• Latest version of SuperSU-v2.46 downloaded and copied onto root of phone and SD Card (for good measure).

• I've copied TWRP-2.8.6.0-condor.img in the correct SDK platform tools folder

• Command line fastboot flash recovery recovery-twrp.img done and received the following message
  target reported max download size of 299892736 bytes
  sending 'recovery' (8652 KB)...
  OKAY [ 0.299s]
  writing 'recovery'...
  OKAY [ 1.047s]
  finished. total time: 1.346s

When I go to the fast load menu holding Power button & Vol Down Button and click on Recovery it goes to a white screen saying Warning Bootloader Unlocked. After a few moments it then goes to Android bot laying on it's back with red exclamation mark over it and the words "No command".
If I leave it for 5 mins it then reboots back to normal stock mode.

My question is what the hell am I doing wrong? I thought I'd researched this properly but obviously not.
How can I get the option to boot from the SuperSU file?

Any help welcome I'm at the end of my tether at this point and out of ideas.