For marinade, stir together orange juice concentrate, cooking oil, honey, mustard, the 1 tablespoon sliced green onion, mint, and hot pepper sauce in a small mixing bowl. Set aside 1/4 cup of the mixture for the relish; cover and chill until needed. Place the steak in a plastic bag set in a shallow bowl. Pour the remaining marinade over meat. Seal the bag and turn to coat the meat with marinade. Marinate in the refrigerator for 12 to 24 hours, turning the bag occasionally.
For relish, combine reserved 1/4 cup marinade, sweet pepper, apple, pear, peach, celery, the 2 tablespoons green onion, and lemon juice in a medium bowl. Cover and chill up to 24 hours.
Remove the steak from the plastic bag, reserving marinade. Grill steak on the rack of an uncovered grill directly over medium coals to desired doneness, turning once and brushing occasionally with marinade until the last 10 minutes of grilling. Allow 18 to 22 minutes for medium (160 degree F) doneness for 1-inch-thick steak, or 36 to 40 minutes for medium (160 degree F) doneness for a 1-1/2-inch-thick steak.
To serve, bias-slice steak into thin strips; arrange on romaine leaves, if desired. Top steak with fruit relish. Makes 6 servings.