Heat oil in a wok or frying pan. Once oil is heated, turn the fire down to medium-low.
Toss in garlic and stir-fry for 1 minute. Adjust the fire to low if needed as you want to infuse the garlic in oil without burning it.
Add sambal belacan. Turn up the fire to medium and stir fry for 1-2 minutes.
Add prawns. Cook until the prawns turn slightly pink (half cooked).
Finally, add in the asparagus and continue to stir-fry on medium heat. Start adding one or two tablespoon of water. Turn up the heat to high. Stir and toss to make sure the asparagus cooks evenly.
Add two more tablespoon of water for more liquid. Add salt and stir occasionally. Asparagus should take about 5 - 7 minutess to cook. Test by using your spatula to cut through one of the spears. It should be easy to cut but still crunchy.
Serve hot with rice. Sometimes I add a squeeze of lime juice over it.