In a Dutch oven, bring 8 cups of water to a boil. Add corn; boil 5-7 minutes or until tender. Drain and immediately place corn in ice water for about 10 minutes. Drain and pat dry; cut the kernels from the cobs.
Meanwhile, rub steak with salt and pepper. In a large skillet, cook steak in 2 tablespoons oil 6-8 minutes on each side or until meat reaches desired doneness (for medium-rare, a thermometer should read 145°; medium, 160°; well-done, 170°).
For dressing, combine vinegar, garlic powder, capers, mustard and remaining oil in a jar with a tight-fitting lid; shake well.
Thinly slice beef across the grain. In a large bowl, combine salad greens, tomato, onion, parsley, corn and beef. Drizzle with dressing; toss to coat. Sprinkle with Parmesan cheese. Yield: 5 servings.