Vietnamese Caramel Fish (Cá Kho Tộ)

In a clay pot or small heavy saucepan over medium heat, add the sugar in an even layer without stirring. Watch as the sugar at the edges begins to melt and turn amber (about 3 minutes). Only then tilt the pan gently to encourage even melting — do not stir with a spoon or it will crystallize. Cook until the caramel is a deep mahogany-brown (not black) and smells of bitter toffee. This is the defining flavor of kho tộ — a dark, slightly bitter caramel that balances the salty fish sauce.

Pour the fish sauce into the hot caramel (spatter warning!). Add the coconut water and stir — the mixture will bubble intensely and the caramel will seize before re-dissolving. Add the shallots, garlic, ginger, chili, and black pepper. Lay the catfish steaks in the pot in a single layer, spooning the caramel sauce over. Cover and braise over medium-low heat for 15 minutes, turning the fish once at the 8-minute mark.

Uncover the pot and increase heat to medium-high. Simmer the sauce, basting the fish continuously with a spoon, for 5–8 minutes until the sauce has reduced to a thick, dark, syrupy glaze that coats every surface of the fish. The pot will begin to sizzle more intensely as the water evaporates. Remove from heat. Scatter green onion over the top. Serve directly from the clay pot with steamed jasmine rice.