For the marinade:

1

In a medium-size bowl, combine the soy sauce, cornstarch, oil, sherry, and sugar. Add the beef and marinate for 20-30 minutes at room temperature. Meanwhile, cook the rice according to package directions.

For the sauce:

1

In a medium-size bowl, combine the soy sauce, sherry, chili oil, cornstarch mixture, and, if desired, the oyster sauce, and set aside.

For the stir-fry:

1

Heat 2 tablespoons of the peanut oil in a 12-inch nonstick skillet or wok over moderately high heat for 1 minute. Add the beef and brown for 2-3 minutes, transfer to a plate.

2

Heat the remaining 2 tablespoons peanut oil in the skillet for 1 minute. Add the ginger and garlic and stir-fry for 30 seconds. Add the asparagus and salt and stir-fry for 1 minute. Add the stock, bring to a boil, cover, and steam for 1 minute. Uncover, return the beef to the skillet, and stir-fry for 30 seconds. Add the sauce and cook, stirring constantly, for 1-2 minutes or until thickened. Add the sesame oil and sprinkle the sesame seeds on top. Serve over the rice.