In a large bowl, combine the lime zest, lime juice, olive oil, chopped cilantro, garlic powder, cumin, chili powder, salt, and pepper to create a marinade.
Add the chicken breasts to the bowl and coat them thoroughly with the marinade. Let marinate in the refrigerator for at least 30 minutes, or up to 2 hours for more flavor.
Preheat a grill or skillet over medium-high heat. Remove the chicken from the marinade, allowing excess to drip off.
Cook the chicken for about 6-7 minutes per side, or until fully cooked (internal temperature should reach 165°F / 75°C). Remove from heat and let rest for 5 minutes.
While the chicken is resting, warm the tortillas on the grill or skillet for about 30 seconds on each side until pliable.
Slice the cooked chicken into thin strips.
Assemble the tacos by placing some chicken strips on each tortilla. Top with avocado slices, shredded red cabbage, and a dollop of sour cream if desired.
Garnish with additional cilantro and a squeeze of lime juice for an extra burst of flavor.
Notes
Letting the chicken marinate longer enhances the flavor.