In a medium saucepan, heat the oil. Add the onion and cook over moderate heat until softened, about 5 minutes. Add the shiitake and cook, stirring occasionally, until softened, about 4 minutes. Add the Chinese sausages and wine and bring to a boil over moderately high heat. Stir in the rice, chicken stock, soy sauce and salt and bring to a boil, stirring a few times.