In a medium bowl, combine chicken (or one cupe white beans for vegetarian option), brown rice, cabbage, and carrots.
In a small bowl, whisk together mayo, olive oil, lime juice, cumin, chili powder, and salt to make the dressing.
Toss dressing into the slaw mixture to coat. Divide in half and store half in the refrigerator for lunch on Day 6.
Serve each portion with 4 lettuce leaf cups.