Pat fish fillets dry and rub with salt for 30 minutes.
Prepare a steamer or a wok with a rack and 5cm of water.
Place fish on a heatproof plate, top with ginger, and steam for 4-5 minutes.
Remove fish and sprinkle with spring onions and soy sauce.
Heat groundnut and sesame oils until smoking and pour over the fish.
Heat a wok, add oil and yellow bean sauce, and stir-fry for 30 seconds.
Stir-fry with soy sauce, salt, and chili powder for 90 seconds.
Pour in stock, add tofu cubes, and cook for 3 minutes.
Add garlic and cornflour paste, cooking until the sauce thickens.
Plate fish with tofu and garnish with coriander and ground peppercorns.