Add the olive oil, harissa paste, minced garlic, paprika, cumin, salt, and black pepper to a large mixing bowl.
Whisk until the ingredients form a well-combined marinade.
Add the chicken pieces and toss thoroughly until every piece is evenly coated with the harissa marinade.
Cover the bowl and refrigerate for at least 2 hours. For deeper flavor, marinate the chicken overnight.
Remove the chicken from the refrigerator shortly before cooking.
Heat a large skillet over medium heat. Since the marinade already contains olive oil, additional oil should not be necessary.
Add the marinated chicken to the hot skillet in an even layer. Avoid overcrowding the pan; cook in batches if necessary.
Cook for approximately 8–10 minutes, turning the pieces occasionally so they brown evenly. The chicken should reach an internal temperature of 165°F (74°C).
Remove the Harissa Chicken from the heat and serve warm with naan, Greek yogurt sauce, and fresh dill or parsley.