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.