In a pot of boiling water, cook corn, uncovered, until tender, 3-5 minutes. Remove; cool slightly. Cut corn from cobs.
Sprinkle steak with salt and pepper. In a large skillet, heat 2 tablespoons oil over medium heat. Add steak; cook until a thermometer reads 135° for medium-rare, 6- 8 minutes per side. Remove from heat; let stand 5 minutes.
In a small bowl, whisk together dressing ingredients. Thinly slice steak across the grain. Place greens, tomato, onion, parsley, corn and steak in a large bowl; toss with dressing. Sprinkle with cheese.