01 - Whisk together 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. Cover and refrigerate for at least 30 minutes, up to 2 hours.
02 - Combine sour cream, mayonnaise, salsa, lime juice, honey, and garlic powder in a small bowl. Whisk until smooth and well blended. Refrigerate until serving time.
03 - Preheat grill or grill pan to medium-high heat. Remove chicken from marinade and discard excess liquid. Grill chicken for 6 to 7 minutes per side until internal temperature reaches 165°F and exterior has light char marks.
04 - During the final 2 minutes of grilling, top each chicken breast with shredded cheese. Close grill lid briefly to melt cheese. Remove from heat and let rest for 5 minutes.
05 - Transfer chicken to serving plates. Drizzle with fiesta sauce, then top with pico de gallo or diced tomatoes. Garnish with fresh cilantro leaves and lime wedges.