For the salad, put the sugar, chilli flakes and water into a small frying pan and cook slowly for 5-6 minutes or until it has a syrup-like consistency. Leave to cool.
To make the pan-fried pork, roll the pork fillet in olive oil, salt and freshly ground black pepper and sear in a hot non-stick frying pan for two minutes on each side.
Remove from the heat and leave to rest for two minutes. Slice into five pieces and arrange in the middle of a plate.
To serve, scatter the watercress round the pork and drizzle with the oriental dressing.