Preheat the oven to 400°F (200°C).
In a bowl, mix harissa paste with olive oil.
Season the chicken with salt and pepper.
Rub the harissa mixture over the chicken.
Place the chicken in a roasting pan.
Add chopped vegetables around the chicken.
Drizzle vegetables with olive oil and season with salt.
Roast in the oven for 45 minutes, basting occasionally.
Check that the chicken is cooked through (165°F or 75°C).
Serve hot with your choice of sides.