In a bowl, mix the olive oil, minced garlic, ground cumin, smoked paprika, chili powder, lime juice, salt, and pepper to create a marinade.
Add the chicken thighs to the marinade, ensuring they are well coated. Let them marinate for at least 30 minutes (or up to 2 hours for more flavor).
Heat a grill pan or regular skillet over medium-high heat. Once hot, add the marinated chicken thighs and cook for about 5-7 minutes per side, or until fully cooked and golden brown (internal temperature should reach 165°F).
Allow the chicken to rest for a few minutes, then chop into small bite-sized pieces.
While the chicken is resting, warm the corn tortillas on a skillet or grill for about 30 seconds on each side until soft and pliable.
To assemble the tacos, place a generous scoop of chopped chicken in the center of each tortilla.
Top the chicken with diced pineapple, chopped red onion, fresh cilantro, and slices of jalapeño for an extra kick.
Finish with a slice of avocado and a dollop of sour cream or Greek yogurt, if desired.
Notes
Serve on a colorful platter with lime wedges and extra cilantro.