Heat a large skillet over high heat. Sprinkle chicken evenly with chile powder, garlic salt, and cumin. Coat pan with cooking spray. Add chicken to pan; cook 4 - 5 minutes, stirring frequently. Remove chicken from pan.
Combine zest, 1 tablespoon juice and sour cream, milk and avocado in a blender or food processor; process until smooth.
Combine remaining 1 tablespoon lime juice, coleslaw, green onions, cilantro, oil and salt, tossing to coat.
Heat tortillas according to directions. (Note: If using flour tortillas, those taste best crisped in a saute pan.) Divide chicken mixture evenly among tortillas. Top each tortilla with about 1 tablespoon avocado mixture and 1/4 cup slaw mixture.