First, marinate the chicken. In a large bowl, mix together the olive oil, lime juice, garlic, cumin, chili powder, salt and pepper. Add the chicken breasts and toss to coat. Cover and refrigerate for at least 1 hour, or up to 24 hours.
Next, make the slaw. In a separate bowl, mix together the mayonnaise, sour cream, and chipotle peppers in adobo sauce. Add the shredded cabbage, cilantro, red onion, and jicama (if using) and toss to coat.
Preheat your grill to medium-high heat. Grill the chicken for 6-8 minutes per side, or until cooked through. Remove from the grill and let rest for 5 minutes.
While the chicken is resting, warm the tortillas on the grill for 30 seconds per side.
To assemble the tacos, place a grilled chicken breast on a warm tortilla. Top with the slaw and serve.