Preheat the oven to 200C/400F/Gas 6.
For the watercress crust, pulse all of the ingredients in a food processor until the mixture is well combined and resembles breadcrumbs. Set aside.
For the pork, season the pork loins all over with salt and freshly ground black pepper
Heat the oil in a large ovenproof frying pan over a medium to high heat. When the pan is smoking, add the pork loins and fry for a few seconds on all sides until lightly browned all over. Transfer the pan to the oven and continue to cook the pork loins for 12-15 minutes, or until cooked to your liking.
Remove the pan from the oven and brush the pork loins all over with the sweet chilli dipping sauce. Cover the pan with aluminium foil and set aside for five minutes to allow the meat to rest, basting it with the sweet chilli dipping sauce at regular intervals.
Meanwhile, for the salad, heat the rice wine vinegar, sugar and salt in a pan over a low to medium heat. When the sugar and salt have dissolved in the liquid, remove the pan from the heat.
Place the turnip, cucumber and shallot into a heatproof bowl. Place the radishes into a separate bowl.
Pour half of the rice wine vinegar mixture over each bowl of salad vegetables. Set aside to pickle for 10 minutes, then drain well.
When the pork has rested, spread the watercress crumb out on a tray and roll the pork through it, so the pork is coated in the watercress crumb. You can serve it like this, or return to the pan to cook the crumb if you prefer.
Carve the pork loins into slices and divide the slices equally among four serving plates. Place a spoonful of the pickled turnip, shallots and cucumber on one side of the pork. Place a spoonful of the pickled radishes on the other side. Garnish the plate with a few sprigs of watercress leaves and coriander cress. Drizzle the plate with a little of the chilli-infused juices left in the pan and olive oil.