- Pour 1/2 cup roasted garlic teriyaki sauce over steak in large plastic food storage bag. Press air out of bag; close top securely. Turn bag over several times to coat steak well. Refrigerate 45 minutes, turning bag over occasionally.
- Meanwhile, cut onion crosswise into 1/2-inch thick slices. Skewer each slice to hold rings together and place in shallow pan. Pour remaining 1/4 cup roasted garlic teriyaki sauce over onion slices, turning to coat both sides with sauce.
- Prepare Roasted Garlic Teriyaki Mayonnaise.
- Grill or broil steak and onion together 4 to 5 inches from heat source 5 minutes on each side (for medium-rare steak), or to desired doneness, brushing occasionally with additional roasted garlic teriyaki sauce.
- Remove skewers from onion.
- Holding knife as flat as possible, cut steak across grain into thin slices.
- To serve, spread rolls with Roasted Garlic Teriyaki Mayonnaise; arrange beef and onion on bottom halves and cover with top halves. *Roasted Garlic Teriyaki Mayonnaise: Blend 1/3 cup mayonnaise, 2 teaspoons Kikkoman Roasted Garlic Teriyaki Marinade & Sauce and 1 teaspoon prepared horseradish; cover and refrigerate.