01 - Combine olive oil, lime juice and zest, minced garlic, chili powder, cumin, smoked paprika, salt, and black pepper in a bowl. Add chicken breasts, turning to coat evenly. Marinate in refrigerator for at least 30 minutes, up to 2 hours for maximum flavor penetration.
02 - While chicken marinates, whisk together sour cream, mayonnaise, salsa, lime juice, honey, and garlic powder in a small bowl until smooth and well combined. Refrigerate until ready to serve.
03 - Preheat grill or grill pan to medium-high heat (approximately 375-400°F). Remove chicken from marinade, allowing excess to drip off. Grill for 6-7 minutes per side until internal temperature reaches 165°F and chicken develops slight char marks.
04 - During the final 2 minutes of cooking, top each chicken breast with shredded cheese. Close grill lid or cover with foil briefly until cheese is melted and bubbly.
05 - Transfer chicken to a cutting board and let rest for 5 minutes to redistribute juices. Plate chicken breasts, drizzle generously with fiesta sauce, and top with pico de gallo or diced tomatoes. Garnish with fresh cilantro leaves and lime wedges on the side.