Trim fat from steak. Sprinkle steak with salt and pepper. Place steak on the unheated rack of a broiler pan. Broil 3 to 4 inches from the heat until desired doneness, turning once halfway through broiling time. Allow 15 to 17 minutes for medium-rare doneness (145 degrees F) or 20 to 22 minutes for medium doneness (160 degrees F). Thinly slice steak.
Divide romaine among 4 dinner plates. Top with sliced meat, red onion, tomatoes, and feta cheese. Drizzle with Lemon Vinaigrette.
In a screw-top jar combine olive oil, lemon peel, lemon juice, oregano and garlic. Cover and shake well. Season to taste with salt and black pepper. Makes about 1/2 cup.