Place beef Ribeye Filets on grid over medium, ash-covered coals. Grill, covered, 7 to 10 minutes (over medium heat on preheated gas grill, covered, 7 to 9 minutes) for medium rare (145°F) to medium (160°F) doneness, turning occasionally.
Meanwhile, combine onion, soy sauce, sesame oil, sesame seeds, red pepper and vinegar in large bowl. Cover and refrigerate.
Cut filets into 1/2-inch cubes. Cover and refrigerate for 3 to 4 hours.
Add filet to soy mixture just before serving; toss gently to evenly coat. Drain steak from soy mixture; discard soy mixture. Garnish steak with garlic, onions, radish, ginger, mayonnaise and cabbage, if desired.
Nutrition information per serving: 225 Calories; 95.4 kcal Calories from fat; 10.6 g Total Fat; 3.1 g Saturated Fat; 0.3 g Trans Fat; 1.3 g Polyunsaturated Fat; 4.4 g Monounsaturated Fat; 70 mg Cholesterol; 699 mg Sodium; 5.3 g Total Carbohydrate; 1.1 g Dietary Fiber; 27 g Protein; 3.1 mg Iron; 498 mg Potassium; 5.3 mg NE Niacin; 0.7 mg Vitamin B6; 2.8 mcg Vitamin B12; 6.4 mg Zinc; 30.7 mcg Selenium; 48.5 mg Choline;