01 - In a large bowl, whisk together the harissa paste, olive oil, lemon juice, lemon zest, garlic, cumin, smoked paprika, salt, and black pepper until well combined.
02 - Add the chicken breasts to the marinade, ensuring they are fully coated. Cover and refrigerate for at least 1 hour, or up to overnight for deeper flavor penetration.
03 - Preheat grill to medium-high heat, approximately 400°F.
04 - Remove chicken from marinade, allowing excess to drip off. Grill for 6–8 minutes per side, or until internal temperature reaches 165°F and juices run clear.
05 - Transfer chicken to a plate, cover loosely with foil, and let rest for 5 minutes to allow juices to redistribute.
06 - Slice and serve garnished with chopped cilantro or parsley and lemon wedges.