Cá kho tộ: caramelized fish in a clay pot

Cá kho tộ is a Southern Vietnamese dish of fish, usually catfish steaks, braised in a small clay pot with homemade caramel, fish sauce, shallots, garlic and plenty of black pepper until the sauce turns thick, dark and glossy. It's salty, sweet and peppery, made to be eaten with lots of plain steamed rice.

It's an everyday home dish rather than restaurant food, and it's one of the classic parts of a Southern family meal alongside a vegetable and a soup.

What does cá kho tộ mean?

• Cá ("kah," rising tone): fish.
• Kho ("kaw," level tone): to braise or simmer in a salty-sweet sauce until reduced.
• Tộ ("toh," heavy tone): a small clay pot or bowl.

So it's "fish braised in a clay pot." The clay pot holds heat evenly and is often brought straight to the table, still bubbling. No clay pot? A small heavy saucepan works fine.

Allergen notes

This dish contains fish and fish sauce. It's naturally free of nuts, gluten and dairy, but check your fish sauce label if you need to avoid additives.

Ingredients (serves 3 to 4 with rice)

• 1 1/2 lb (680 g) catfish steaks, about 1 inch (2.5 cm) thick (or another firm fish)
• 3 tbsp fish sauce
• 2 tbsp sugar for the caramel, plus 1 tbsp for seasoning
• 3 shallots and 3 cloves garlic, minced
• 1 tsp freshly ground black pepper, plus more to finish
• 1/2 cup (120 ml) coconut water or plain water
• 1 or 2 Thai chilies, sliced, and 2 scallions, cut into lengths

If you already have Vietnamese caramel sauce (nước màu), use 1 to 2 tbsp of it instead of making caramel in step 2.

Steps

• 1. Marinate the fish. Rinse the fish and pat dry. Mix with 2 tbsp fish sauce, 1 tbsp sugar, half the shallots and garlic, and the pepper. Marinate 30 minutes in the fridge.
• 2. Make the caramel. In the clay pot or saucepan, heat 2 tbsp sugar with 1 tbsp water over medium heat, without stirring, until it turns a deep amber, about 4 to 6 minutes. Watch closely; it goes from amber to burnt quickly.
• 3. Build the sauce. Lower the heat and carefully add the remaining shallots and garlic. They'll sizzle. Stir for 30 seconds.
• 4. Add the fish. Lay the fish pieces in a single layer and turn them once to coat in caramel. Pour in any leftover marinade, the remaining 1 tbsp fish sauce and the coconut water.
• 5. Braise. Bring to a boil, then lower to a gentle simmer. Cook uncovered 25 to 35 minutes, spooning sauce over the fish now and then and turning gently once. Avoid stirring, which breaks the fish.
• 6. Reduce. When the sauce is thick enough to coat a spoon, turn up the heat for a minute or two to glaze. Taste and adjust with a little sugar or fish sauce.
• 7. Finish. Add chilies, scallions and a generous grind of black pepper. Serve in the pot.

How is it served?

Cá kho tộ is a strong, concentrated dish, so it's paired with mild partners:

• Plenty of hot steamed rice.
• A light, sour soup like canh chua, a common Southern pairing.
• Boiled or raw vegetables, such as cucumber or boiled greens, to balance the salt.

Tips

• Catfish vs other fish. Catfish is traditional in the South. Firm fish such as basa, swai or salmon steaks also work. Delicate fillets like tilapia tend to fall apart.
• Coconut water. It adds gentle sweetness and is common in Southern braises. Water is fine too.
• Clay pot care. Heat clay pots gradually and avoid moving them from hot to cold surfaces. Follow the maker's instructions; some need soaking before first use.
• Go easy on salt. Fish sauce strength varies by brand. Season lightly and adjust at the end. See fish sauce: how to choose and use nước mắm.

Storage

Cá kho tộ keeps well in the fridge for up to 3 days, and many people think the flavor deepens overnight. Reheat gently with a splash of water.

Related braises

The same kho technique is used for pork. If you like this dish, try thịt kho trứng: braised pork and eggs, which uses a similar caramel base with a longer, gentler simmer.

When making caramel for the first time, keep a small cup of water nearby; a splash stops the cooking instantly if it darkens faster than you expect.