In a bowl, combine the orange juice, lime juice, minced garlic, cumin, oregano, smoked paprika, salt, and pepper. Mix well to create the marinade.
Place the chicken thighs in a resealable plastic bag or a shallow dish, and pour the marinade over the chicken. Seal the bag or cover the dish and marinate in the refrigerator for at least 1 hour, preferably overnight for maximum flavor.
Preheat your grill or a skillet over medium-high heat. Add olive oil after the skillet is hot.
Remove the chicken from the marinade, letting any excess drip off. Grill or cook the chicken for about 6-7 minutes per side, or until fully cooked and the internal temperature reaches 165°F (74°C).
Once cooked, let the chicken rest for a few minutes before slicing it into strips.
Meanwhile, warm the corn tortillas on the grill or in a separate skillet until they are pliable.
To assemble the tacos, lay a few slices of chicken on each tortilla, top with shredded red cabbage and avocado slices.
Garnish with fresh cilantro leaves and serve with lime wedges on the side for squeezing over the tacos.
Notes
Marinate the chicken overnight for the best flavor.