Preheat your broiler. Sprinkle salt and pepper on both sides of the steak. Put the steak on a broiler pan and place about one-inch below broiler. Let cook 3-4 minutes. Flip and let cook for another 3-4 minutes. Remove from broiler and let rest for 5 minutes. Slice thinly.
In a large bowl, whisk together the oil, vinegar, salt, pepper, and oregano. Add the lettuce, tomatoes, olives, onions and feta cheese, and toss with the dressing.
Place the tossed salad into a serving bowl. Top with sliced steak. Serve with a side of pita bread, if desired.