Sterilize your glass jars by boiling them in water for 10 minutes. Let them cool completely.
Clean the fresh shrimp by removing the heads, tails, and legs. Keep the shells on. Using a toothpick, remove the black vein from the back of each shrimp. Cut each shrimp into 2-3 pieces.
Put the chopped shrimp in a bowl. Add rock salt, brown sugar, and chili powder. Mix everything well, gently pressing the shrimp to absorb the seasonings. Cover and let it marinate for 1 hour.
Cook your rice with extra water than usual - you want it slightly softer than normal rice. Spread the cooked rice on a tray and let it cool completely.
Mix the cooled rice and marinated shrimp in a large bowl until well combined.
Pack this mixture into your sterilized jars, filling up to the neck. Press down firmly to remove air pockets. Wipe the jar rims clean with paper towels. Place plastic wrap on top of each jar before closing the lids tightly.
Store the jars in a dark cabinet at room temperature for 7 days. After a week, you should see liquid at the bottom of the jars. When you open them, they shouldn't smell bad.
After checking, mix the contents with a clean spoon, close the jars tightly, and return them to the dark cabinet for another 7 days.
After the full 14 days, heat olive oil in a large pan. Cook minced ginger, garlic, and onions until soft and fragrant.
Add your fermented shrimp mixture and bring to a boil while stirring for 5 minutes.
Pour in the water and reduce heat to medium. Let it simmer for 40 minutes, stirring occasionally until it reaches your desired thickness.
Turn off the heat and let it cool slightly. Transfer to clean jars for storage and keep in the refrigerator, where it will last for 30 days.
Serve as a sauce with fried eggplant, vegetables, or fish. Always use a clean spoon when serving.