Combine the cornstarch with the sherry.
Pour the oil into a wok. Heat over high heat. Add the minced black beans and ginger. Stir fry for 10 seconds then add the chicken stock, oyster sauce and soy sauce.
Bring to a boil and reduce for 2 to 3 minutes, stirring occasionally. Mix the cornstarch and sherry and add to the sauce, stirring until thickened.
Allow the sauce to cool, then refrigerate in a closed container. Add the garlic and scallion when using the sauce.
Serve warm over vegetables such as kale, carrots, vegetables, steamed rice or thin noodles.
