1. In a small bowl, combine the chicken broth, ketchup, soy sauce, oyster sauce, salt, and 1 tablespoon of the sherry. Heat a wok or large frying pan over moderately high heat until very hot. Add the bell peppers and stir-fry until starting to blacken, about 5 minutes. Remove.
2. Bring a medium pot of salted water to a boil. Stir in the rice and boil until just done, about 10 minutes. Drain.
3. Meanwhile, toss the shrimp with the remaining 2 tablespoons sherry and the cornstarch. Heat 1 1/2 tablespoons of the oil in the wok or frying pan over moderately high heat. Add the shrimp and stir-fry until just done, 3 to 4 minutes. Remove the shrimp and add the remaining 1 1/2 tablespoons oil. Reduce the heat to moderate and add the charred bell peppers, the garlic, ginger, the chopped scallions, and the red-pepper flakes. Cook, stirring, until soft, about 3 minutes.
4. Increase the heat to high. Add the broth mixture and boil until thickened, about 2 minutes. Add the shrimp and sliced scallions and just heat through. Drizzle the sesame oil over the top. Serve the shrimp with the rice.
Wine Recommendation: A German riesling will be a knockout here. If you're keeping the heat subdued, a Pfalz kabinett will work fine. If you increase the pepper, go to a sweeter spätlese or even an auslese.