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. 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 creamy. Refrigerate until serving.
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 chicken has nice char marks.
04 - During the final 2 minutes of cooking, top each chicken breast with shredded cheese. Cover grill briefly to melt cheese. Remove chicken and let rest for 5 minutes before serving.
05 - Plate chicken breasts and drizzle generously with fiesta sauce. Top with pico de gallo or diced tomatoes, fresh cilantro leaves, and lime wedges on the side.