In a skillet heat the oil over moderately high heat and in it stir-fry the garlic, the gingerroot, and the red bell pepper until the pepper is softened. Add the beans and stir-fry the mixture for 2 minutes. Add the Sherry and boil the mixture, stirring occasionally, for 10 minutes. In a small bowl dissolve the cornstarch in 2 teaspoons cold water, whisk it into the mixture, and simmer the sauce until it is thickened slightly. Add black pepper to taste and serve the sauce over asparagus. Makes about 1 1/4 cups. Gourmet April 1990