Slice the steak across the grain into 16 strips, about 1/2 inch thick. Pound each to about 1/8 inch, then season with salt and pepper. Place 1 spear of asparagus and 1 scallion across the short end of a strip, roll steak around vegetables and secure with a toothpick. Rinse and repeat.

Combine the rice vinegar, soy sauce, sugar and sesame oil. Pour it over beef rolls and marinate for at least 10 minutes.

Process the red bell pepper, distilled vinegar, sugar, cornstarch and red pepper flakes until smooth. Transfer to a saucepan, boil for about 5 minutes, and cool to room temperature.

Remove beef from marinade, and broil for about 5 minutes under high heat. Boil the marinade until syrupy, about 5 minutes.

Remove toothpicks from steak rolls and top with boiled marinade. Serve with the red bell pepper dip.