Place the belacan in a small frying pan on medium-low heat. Flatten it as much as you can to get as much of the surface area roasted as possible; it will stick to the back of your spatula. Just scrape it off and add back to the pan.
Turn the heat down to low and roast for about 5 minutes. Flip it over halfway. If it's in bits, just scrape and flip as much as possible, but don't worry too much if you can't.When done, tip into the mortar after pounding the chillies. If using chopper, just tip with the chillies.
With a Pestle and Mortar
If you are using a pestle and mortar, start by pounding the chillies, sugar and salt.
When it has reached the semi coarse stage, add the shrimp, pound for a minute.
Then finally, add the lime juice and zest and mix well.
Store in a clean jar in the fridge for up to 5 days.
In a Chopper
If using a chopper, like me, place everything in and chop to a smooth-ish mix, as in the image. Or keep it coarse if you prefer.
Video
Notes
Sambal belacan is a much loved chilli paste or condiment from Singapore and Malaysia, with shrimp paste.