Choose catfish tail pieces with a little fat. Pour boiling water over the fish to remove the slimy layer, then scrape, rinse well, and cut into chunks.

Marinate the fish with minced garlic, black pepper, fish sauce, caramel sauce, sugar, and MSG. Mix well to let the flavors absorb.

Heat a pan with oil, add the fish, and sear until firm. Pour in the coconut water and cook, occasionally skimming off any foam. Once the fish is cooked, adjust seasoning to taste. Add a few whole chili peppers if desired. If making a large batch, leave some sauce to reheat later; if serving immediately, reduce the sauce a bit more before removing from heat. Transfer to a plate and sprinkle with black pepper.