Briefly rinse anchovies and drain well in a colander. Heat enough oil in a wok and fry anchovies for 3-4 minutes to brown until crisp. Remove with a slotted spoon and leave aside.
Heat a clean wok until it begins to smoke and put raw peanuts and salt in to fry.
Lower the heat and stir-fry constantly for at least 5-6 minutes. Fry peanuts with a quick to-and-fro motion until they begin to blister and turn brown. Test by tasting one peanut to make sure that the peanuts are not still raw inside.
Remove and place peanuts on a large flat tray and allow to cool for at least 15-20 minutes. This makes it easy for you to handle without burning your palm. Rub handfuls of peanuts between your palms until all the skin has been removed. Hold the tray in front of you and flick it up to winnow away the skin. Put peanuts aside.
Preheat 1-2 tbsp oil in a clean wok, add sugar and stir-fry for 20-30 seconds.
When sugar starts to melt, add pre-fried anchovies, dried chillies, thick soy sauce, salt and pepper. Stir constantly, then add peanuts to combine. Fry until well combined.
Dish out and leave to cool slightly before serving or storing in glass jars.