Make the marinade: peel the ginger and slice it very thinly. Mix the salt and rice wine.
Make 3-4 parallel cut across the fish on both sides, then rub with the salt & rice wine. Fill the cavity with the ginger strips. Marinate for 20-30 minutes.
Meanwhile, prepare the vegetables and spices: slice the pepper into thin strips, chop the ginger and garlic, slice the spring onions diagonally.
Remove the ginger from the fish cavity. Wipe the fish with paper towel, then rub the starch into the cuts.
Heat 2 Tbsp of oil in a wok over a high heat, add a little salt (so the fish won't stick to the wok).
When the oil is smoking hot, place the fish carefully in the oil and fry for 3-4 minutes then turn over and fry for another ¾ minutes until golden.
Transfer the fish to a kitchen paper towel lined plate.
Wipe the wok with paper kitchen towels and heat the remaining oil. Add the chilli bean sauce, stir-fry for a minute, then add the chopped ginger, garlic, spring onions, and chilli flakes (if used). Stir-fry for 2-3 minutes.
Pour in the stock and bring to the boil. Add the rice wine and sugar, then carefully slide in the fish.
Cook for 3-4 minutes, while continuously basting the fish with the sauce. Turn it over and cook for a further 3-4 minutes while basting.
When the sauce is thick and sticky, slide the fish onto a serving plate. Add the sesame oil to the sauce and pour over the fish.
Serve hot with steamed rice and stir-fried veggies.