1⁄4 cup granulated sugar
1 1⁄2 tsp. light brown sugar
3 tbsp. fish sauce
1⁄2 tsp. kosher salt
1⁄4 tsp. freshly ground black pepper
2 cloves garlic, chopped
4 1"-thick catfish or salmon
steaks (about 8 oz. each)
1 tbsp. canola oil
1 cup strained fresh or canned unsweetened
young coconut juice (not milk)
5 Thai chiles, stemmed and halved crosswise
4 scallions, cut into 1" lengths
2 cups steamed white rice
1. Combine granulated sugar and 1⁄4 cup water in a 1-qt. saucepan over medium-low heat and cook, without stirring, until sugar dissolves and sauce becomes dark brown, about 25 minutes. Remove pan from heat and let cool slightly. Vigorously stir in brown sugar, fish sauce, salt, pepper, and garlic to make a marinade. Put the fish into a shallow baking dish and pour marinade over the steaks, flipping to coat; set aside to let marinate for 15 minutes.
2. Heat oil in a 12" skillet over medium-high heat. Add the fish and marinade and cook, flipping fish once, until marinade thickens, about 5 minutes. Add coconut juice and bring to a boil. Reduce heat to medium-low and simmer, flipping the fish once and basting with the cooking liquid, until the liquid thickens slightly and the fish is cooked through, about 15 minutes. Using a spatula, transfer fish to 4 serving plates. Raise heat to medium-high, add chiles and scallions, and cook until scallions soften, 2–3 minutes. Spoon sauce over fish and serve with rice and stir-fried greens, such as bok choy.