1. If using unsliced beef, remove from the freezer and slice to 1/8-inch thickness. In a medium bowl, mix together the sesame seeds, oil, sugar, sukiyaki sauce, salt, black pepper, red pepper, scallion, and garlic. Add beef, and let marinate, covered, for 30 minutes or up to overnight, in the refrigerator.

2. Preheat indoor barbecue grill to medium-high. Place marinated beef on grill, and cook until beef is brown and the edges begin to crisp, 3 to 4 minutes per side. (Alternatively, the meat may be broiled about 5 minutes per side.)

3. Place 1 tablespoon rice and 1 slice of beef on each lettuce leaf. Add a drop of bean paste, if you desire. Wrap like a taco, and serve immediately.