A whole fish scored on both sides, seasoned, floured and fried five to seven minutes a side. Fifteen minutes for two, and the three cuts are what let the heat reach the middle.
The three cuts on each side are the technique of the whole recipe. A whole fish is much thicker at the spine than at the tail, so without them the thin parts overcook while the middle is still raw. Cutting down to the bone lets the heat in and the fish cooks evenly. Dry the fish properly before it goes anywhere near the flour. Water on the skin turns the flour to paste, stops it browning and makes the oil spit. Kitchen paper, both sides, inside as well. Flour is not a batter here. It is a thin coating that browns and stops the skin sticking to the pan, which is why a quarter of a cup is enough for two fish. Judge it at the thickest part, just behind the head. When the flesh there is opaque all the way to the bone, the fish is done. Mojarra is what this would be in Colombia, usually served whole with coconut rice and patacones on the coast.