Place the fish pieces in a large bowl.
Pour the seawater (or salted water) over the fish. Ensure the fish is fully submerged. If not, add a little more water.
Cover and let it marinate in the refrigerator for at least 2 hours or overnight. This process helps to slightly ferment the fish and infuse it with the saltwater flavor.
In a separate bowl, combine the minced garlic, chopped chilies (if using), grated ginger, and freshly squeezed lime or lemon juice.
After marinating, drain the fish pieces and rinse them thoroughly under cold water to remove excess salt.
In a large mixing bowl, combine the marinated fish pieces with the aromatic mixture.
Pour the coconut cream over the fish and gently mix until everything is well combined.
Transfer the fafaru to a serving dish.
Enjoy your meal!