It's normal for the recovery to inform you that you're not rooted, it'll suggest that you install superuser but there's no point doing that in your case because you have no working OS installed. Did you at any point perform a factory reset from the bootloader? If so, you've corrupted the internal storage (known bug on modified Evitas) and will need to wipe it with TWRP.

Sent from my Evita
OnePlus One | crDroid/AK | TWRP 2.7.1.1

Do not PM me asking for assistance, that's what my Q&A thread is for!