Preparation

• In a small bowl, mix the 2 tsp. cornstarch with the 2 Tbs. vinegar. Add the broth, soy sauce, and ketchup. Season the fish with 1/2 tsp. salt and 1/2 tsp. black pepper. Spread the remaining 1/2 cup of the cornstarch on a plate, and put the eggs in a wide bowl. Dredge the fish in the cornstarch. Heat 2 Tbs. of the oil in a 12-inch nonstick pan over medium-high heat until shimmering hot. Soak the fish in the egg for a couple of seconds, then add to the pan. Cook, flipping after 3 min., until the fish is browned and a little firm to the touch, about 5 minutes total (it should not be cooked all the way through). Transfer the fish to a large plate.
• Add the remaining 1 Tbs. oil to the pan, then add the chiles, white parts of the scallions, and ginger. Cook, stirring, until the scallions become translucent and browned in places, about 2 min. Give the cornstarch mixture a quick stir and then pour it into the pan. It should come to a boil and thicken quickly. Reduce the heat to medium-low, return the fish to the pan, and flip it a couple of times to coat it in the sauce. Cover the pan, leaving the lid slightly ajar, and cook until the fish is just cooked through and starting to flake, 3 to 5 min. Taste the sauce for salt and vinegar and add more to taste. Serve immediately with the sauce spooned over the fish and sprinkled with scallion greens.

Serve with basic white rice.