Heat oven to fan / gas 200C/180C 6. Mix the harissa paste and the vinegar in a big jar, then add the chicken and onions. Spread the combination for 35 minutes in a big roasting tin and roast, turning at least once. Add the peppers and feta in the final 10 minutes, then sprinkle with the pine nuts just before the end of the cooking period. Serve with couscous and pan juices.