01 - In a large bowl, whisk together the lime juice, lime zest, olive oil, garlic, chili powder, cumin, smoked paprika, salt, and black pepper. Add the chicken breasts and turn to coat evenly. Cover and refrigerate for at least 20 minutes, up to 2 hours.
02 - Preheat a grill or skillet over medium-high heat. Remove the chicken from the marinade and cook for 6 to 7 minutes per side until the internal temperature reaches 165°F.
03 - While the chicken cooks, combine the diced avocados, tomato, red onion, cilantro, lime juice, and salt in a bowl. Gently toss to combine without mashing the avocado.
04 - Transfer the cooked chicken to serving plates. Sprinkle shredded cheese over each breast while hot so it melts slightly.
05 - Spoon a generous portion of the avocado mixture over each chicken breast. Garnish with lime wedges and extra cilantro. Serve immediately.