Preheat the oven to 180°C/350°F/gas 4. Lightly oil a large ovenproof dish. Place the vegetables and chives in the dish and arrange the lemon slices on top. Lay the salmon fillets on top of the lemon slices. Drizzle over one tablespoon of olive oil and season well. Cover the dish with foil and place it in the oven for 15–20 minutes, or until the salmon is cooked through. Divide the salmon and vegetables between warmed serving plates. Serve with baked sweet potatoes and natural yoghurt.