Heat the oil in a wok over a moderate heat. Add the ginger and garlic with the black beans and stir-fry for 2 minutes, then stir in the lemon juice, soy sauce, sugar and rice wine.
Lay the fish fillets in the sauce in the wok. Simmer gently for 20–25 minutes, by which time the fish should be cooked through. Sprinkle the spring onions over the top of the fish and cook for just a few minutes longer.
Transfer the fish and sauce to a warm serving dish or, alternatively, divide into 4 portions and serve on individual plates. Garnish with the red pepper strips and spring onions and serve immediately with rice noodles, if liked.