Put the sweet potato in a saucepan of salted water. Add the star anise and the cinnamon stick, bring to the boil and simmer until you can smell the cinammon and the star anise.
Meanwhile, chop the onions into rings (go from top to bottom without chopping the onion lengthways at any point) and put the wok on the flame over medium low heat - adding the ghee. When the ghee has turned completely clear, add the onions, spices and raisins to the wok.
Chop the ginger roughly into large chunks, scoring the sides of the chunks so that the flavour will seep out into the mix. Give everything a good stir, put a lid over it and take the heat down so it's quietly sizzling without burning. Drain the liquid off the sweet potato pieces and leave them to dry for a couple of minutes before adding them, with the cinnamon and star anise, to the wok.
Now add the fermented chilli paste. Stir again and put the lid on. You don't want to over-stir this dish or the potato pieces will just break up and turn into a sticky mess, so just make sure everything is coated with spices and oil, and put the lid back on the wok.
When the red onions are going clear and the potato pieces are beginning to brown, put the mangetout, the bok choi and the baby sweetcorns into the wok. Stir everything once and replace the lid. When the leaves of the pak choi turn dark green and begin to wilt, it is time to give everything a final stir and throw the salted, roasted peanuts into the mix. Add salt and pepper to taste, and serve.