Heat the olive oil in a large pot over medium heat. Add the onion and garlic and cook for 3 to 4 minutes until the onion softens.
Add the chicken pieces to the pot. Season with salt and pepper, then cook for 5 to 6 minutes, stirring occasionally, until the chicken is lightly browned on all sides.
Stir in the harissa paste, cumin, and smoked paprika. Cook for 1 minute to toast the spices.
Add the carrots, parsnips, and chicken broth. Bring the mixture to a boil, then reduce the heat to low and simmer uncovered for 25 to 30 minutes until the vegetables are tender and the chicken is cooked through.
Taste and adjust salt and pepper if needed. Ladle the stew into bowls and top with fresh cilantro before serving.