In a small bowl, combine the pork mince, sherry and 1 teaspoon cornstarch; set aside.
In a separate small bowl, combine black beans, chilli paste, cayenne pepper, soy sauce, garlic and ginger; set aside.
Heat a large frypan over medium heat. If pork is lean, add 1 tablespoon oil. Cook pork until evenly browned. Stir in black bean mixture, tofu, and peas. Pour in chicken stock, and bring to a boil. Stir in dissolved cornflour, and cook until thickened.