Preheat the oven to 180C. Cut the onion into wedges, the courgette & sweet potatoes into chunks. Roughly chop the walnuts.
Put the chicken, vegetables and walnuts into a roasting tin. Season with salt and pepper.
Mix the Cajun seasoning, oil and honey together, then drizzle over the chicken and vegetables and, using a silicon brush, cover the chicken and vegetables evenly.
Roast for about 40 minutes until the vegetables are tender and the chicken is cooked through.
Serve warm, perhaps with some green salad on the side.