Start by placing the catfish fillets in a shallow dish and pour in the dark soy sauce and fish sauce. Allow the fish to marinate for about 10 minutes, turning occasionally.

In a small pan, heat a tablespoon of oil over medium heat. Once shimmering, add the minced shallots and sauté for about 30 seconds until shiny and fragrant.

Add the minced garlic to the sautéed shallots and cook for an additional 30 seconds. Stir frequently to prevent burning.

Carefully add the marinated catfish pieces along with the remaining marinade and coconut water to the pan. Increase the heat slightly to bring to a boil.

Once boiling, lower the heat to a gentle simmer. Cook uncovered for about 20 minutes, stirring occasionally.

After 20 minutes, carefully flip the catfish pieces to ensure even cooking. Add chopped green onions and continue to simmer for another 10 minutes.

Finally, sprinkle freshly cracked black pepper before serving, ideally over a steaming bowl of rice.