Heat the oil in a large skillet over high heat.
Add the onion, ginger, garlic and chili and cook for 2 minutes.
Add the pork mince and cook for 2 minutes or so until white all over, breaking up the meat with a wooden spoon.
Add the sugar and fish sauce.
Stir, then leave it to cook without touching until all the juices cook out and the pork starts caramelised - about 2 minutes. Then stir it and leave it again, without stirring, for around 30 seconds to get more caramelisation. Repeat twice more until caramelised to your taste. (we do it 3 times)
Serve over rice or vermicelli noodles, garnished with sliced scallions/shallots. For a low carb, low cal option, try Cauliflower Rice! I like to have chunks of plain cucumber and carrots on the side which is a classic way of making Vietnamese bowls.