Preheat oven to 220°C (200°C fan–forced). Line a baking tray with baking paper. Place salmon on tray, skin side down. Season and roast for 10-13 minutes, until cooked to taste.
Meanwhile, cook pak choy in a saucepan of boiling water for 2 minutes, until just wilted. Drain.
Combine remaining ingredients and drizzle over salmon. Serve with pak choy.