Use a cleaver or knife to finely mince the shrimp into a very fine paste. This process entails chopping and folding the shrimp paste over and onto itself, and continuing to chop. Transfer the shrimp paste to a bowl.
Chop the scallions. Set aside half of the green portion for the sauce. Add the rest of the chopped scallion to the shrimp, along with 1 teaspoon salt, 2 tablespoons vegetable oil, 1/2 teaspoon sesame oil, 1 1/2 tablespoons cornstarch, 2 teaspoons Shaoxing wine, and white pepper to taste. Use a fork to beat/whip the shrimp until it is smooth and all the ingredients are well-combined.
Pop the stems off the bell peppers and follow the lines of each pepper to cut into 3-5 segments. Remove the seeds. If using long hot green peppers, just cut them in half lengthwise and remove the seeds.
Stuff each pepper segment with the shrimp mixture until the filling is even with the edges of the peppers. You can also trim the ends of the peppers to ensure they are flush and at the same level of the filling. This will make the peppers easier to cook.
Heat a tablespoon of oil in a wok or skillet over medium high heat and place the peppers in the oil, stuffing side down. Cook until they are browned, about 2 minutes. Turn the peppers over to sear the bottoms for another 2 minutes, turning the heat down if they start to get too dark. If using the long hot green peppers or another variety of thin-fleshed pepper, simply transfer them to the serving plate.
If using bell peppers, which have thicker flesh and take longer to cook, add 2 tablespoons of water to the pan, cover, and steam for another 2 minutes, or until the peppers are just tender. Set aside on a serving plate.
It's time to make the sauce, which only takes a couple minutes. Heat the wok over medium heat and add the oil, garlic and fermented black beans. Stir-fry for a few seconds and add the shaoxing wine. When the wine is bubbly, add the rest of the sauce ingredients (except the cornstarch slurry) and bring to a simmer. Once simmering, add the cornstarch slurry gradually until the sauce is thick enough to coat a spoon. Stir in the reserved scallions and spoon the sauce over the peppers to serve.