Prepare the ingredients.

Apply some cooking oil on the mortar then add featherback fish. Add shallots, garlic, white stems of scallions, dill, ground black pepper, seasoning powder into the mortar and mix well. You can use hands to knead the fish paste until combined well. The more you knead, the more chewy the fish cake will be. After kneading, smear the fish paste with a pestle or spoon in about 10 minutes. Add fish sauce and continue smearing in 5 minutes. When adding fish sauce, fish paste can be crumbled a bit, but no worry! Fish paste will be chewy again after being smeared again.

Add 1 spoon of cooking oil into the mortar (to make fish soft when fried). Continue smearing. Total time for smearing should be 20 minutes to have delicious fish paste. You can mix all ingredients and smear in 10 minutes if you don't have much time. You can use a powder mixer (or food processor) to puree but it won't be as chewy as done by hand. When you're done with pureeing, fish is OK when it turns white.

Store the fish paste in plastic bags, big or small as desired. Use a cutting board to press hard and push out evenly to 4 corners. It should be 1-1.2 cm thick to be good when fried.

You can fry the whole piece, or cut into smaller pieces or shape in balls as desired. Or store separated parts in freezer to cook later.

For me, I fry the whole piece of fish paste and cut into bite-size pieces. This dish is best served hot. Use with chili dipping sauce and rice. For kids, use salty fish sauce with ground black pepper instead. Or use chili garlic fish sauce to your liking.