Wash the catfish with lemon and salt to remove any fishy smell and slime, then cut into serving-size pieces.

Place 4 cloves of garlic and 2 chili peppers (adjust for desired spiciness) in a mortar and pound into a paste using a pestle. Note: Do not chop with a knife, as pounding helps the fish absorb the flavors better. After pounding, add 4 tablespoons fish sauce, 3 tablespoons sugar, and the other seasonings to the mortar and mix well. Pour the marinade over the fish and mix to coat evenly.

Marinate for 30 minutes to 1 hour.

Add 1-2 tablespoons vegetable oil to a pan or pot, then add 1 tablespoon sugar to create a caramel color. Watch carefully—when the sugar turns a deep amber, add the fish (do not pour in the marinade liquid, as it can make the dish fishy). Quickly add just enough water to barely cover the fish—do not add too much, as the fish cooks quickly. Alternatively, you can use pre-made caramel sauce sold at Asian markets.

After adding water, season with 1-2 tablespoons fish sauce, 1 tablespoon sugar, and adjust other seasonings to taste.

Cover and simmer for 15-20 minutes, then turn off the heat.