For dressing, in a screw-top jar combine salad oil, vinegar, sesame oil, sugar, grated ginger, red pepper, and garlic. Cover and shake well.
Place steak in a plastic bag set in a shallow dish. Pour 1/3 cup dressing into plastic bag. Close bag and turn to coat well. Marinate in the refrigerator for 6 to 24 hours, turning bag occasionally. Cover and refrigerate remaining dressing.
Remove steak from bag, reserving marinade. Place steak on an uncovered grill directly over medium-hot coals for 6 minutes. Turn and grill to desired doneness, allowing 6 to 9 minutes more for medium.
For salad, in a very large bowl combine romaine or leaf lettuce, curly endive or escarole, sweet pepper strips, tomatoes, and enoki mushrooms. Toss lightly to mix. Divide salad mixture among 4 plates. Thinly slice grilled steak and divide into 4 equal portions. Top each salad with meat. Sprinkle with pistachio nuts. Drizzle the reserved dressing over salads. Makes 4 main-dish servings.