This is by far my favorite fresh Mex spot in Phoenix. I used to go here all of the time when I lived in the North Valley. I still make it a point to stop by anytime I'm in the area.
The restaurant is set up much like Chipotle- there's an assembly line with multiple clerks working on your order. You tell them what you want, and they assemble a huge burrito for you. The only down side is you're charged for specialty items like green chiles, but it is so worth it.
My big veggie burrito costs about $7 and is perfect before an afternoon nap.
Here is my go to order-
Veggie burrito with green chiles, chipotle barbeque sauce, rice, black beans, corn, mild salsa, ranch dressing, and maybe some mango salsa if I'm feeling feisty.
Cafe Rumba is definitely worth checking out if you are near the Arrowhead area!