Place a large nonstick skillet over medium-high heat until hot. Add sesame seeds. Cook, stirring constantly, 1 to 2 minutes or until toasted. Set aside.
Snap off tough ends of asparagus. Remove scales from stalks with a knife or vegetable peeler, if desired. Cut asparagus diagonally into 1-inch pieces. Set aside.
Coat skillet with cooking spray; place over medium-high heat until hot. Add beef, and cook, stirring constantly, 3 minutes or to desired degree of doneness. Drain beef, and pat dry with paper towels; wipe drippings from skillet with a paper towel.
Coat skillet with cooking spray; place over medium-high heat until hot. Add asparagus, mushrooms, crushed red pepper, and green onions. Cook, stirring constantly, 3 to 4 minutes or until asparagus is crisp-tender. Return beef to skillet, and add teriyaki sauce and cook, stirring constantly, 1 additional minute.
Place 1/2 cup rice on each of 2 individual serving plates. Spoon meat mixture evenly over rice; sprinkle with sesame seeds.