01 - In a small bowl, whisk together the olive oil, lime juice, minced garlic, smoked paprika, cumin, salt, and black pepper until well combined.
02 - Place the chicken breasts in a shallow dish or a resealable plastic bag. Pour the marinade over the chicken, turning each piece to coat evenly. Allow to marinate at room temperature for at least 10 minutes, or refrigerate for up to 2 hours for more pronounced flavor.
03 - Preheat an outdoor grill or grill pan to medium-high heat, approximately 400°F.
04 - Grill the chicken breasts for 6 to 7 minutes per side, or until fully cooked through and the internal temperature registers 165°F on an instant-read thermometer.
05 - While the chicken grills, combine the diced avocados, tomato, red onion, cilantro, lime juice, salt, and pepper in a medium bowl. Toss gently to avoid mashing the avocado.
06 - Transfer the grilled chicken to serving plates and spoon the avocado mixture generously over each breast. Serve immediately, garnished with additional cilantro or lime wedges if desired.