Preheat oven to 220C. Combine cooking wine, hoisin sauce, lime juice, soy sauce, ginger, garlic, chilli, star anise, cinnamon stick and 250ml (1 cup) of the water in the bottom of a heavy-based roasting pan. Stir to combine. Add onion. Place pork, rind-side up, on top of onion, making sure the liquid doesn’t cover the rind.
Drizzle the oil over the pork rind. Sprinkle with salt. Season with pepper. Rub the salt and pepper into the cuts. Roast for 30-40 minutes or until the rind crackles. Pour 125ml (1/2 cup) of remaining water into base of pan.
Reduce oven to 160C. Roast, adding remaining water halfway through cooking, for 2 hours or until the pork is very tender. Transfer to a chopping board. Rest for 10 minutes.
Whisk the vinegar, sugar and salt in a bowl. Add the cucumber and nashi pear and toss to combine. Set aside for 3 minutes to develop the flavors. Drain, discarding excess liquid. Transfer the cucumber mixture to a bowl. Add the watercress and toss to combine.
Drizzle the pork with a little of the pan juices. Serve with the salad.