Marinate the chicken - In a small bowl, mix together harissa, olive oil, smoked paprika, lemon juice, salt and pepper. Coat the chicken and set aside while you prep the veg.
In a roasting tin, scatter the sweetcorn, red onion, red pepper and courgette. Drizzle with a little oil, season, and toss together.
Add the chicken thighs on top of the vegetables.
Roast in an oven at 200°C (180°C fan) for 30–35 minutes until the chicken is cooked through and the veg is lightly charred.
In the meantime, make the herb yoghurt. In a small bowl add the yoghurt, mint, parsley, garlic, lemon juice, salt and pepper and mix together.
Serve the herb yoghurt drizzled over the chicken and vegetables or serve on the side.