Sprinkle salt and pepper over steak. Brown steak on one side in hot oil in a skillet. Place steak, browned side down, on a baking sheet; surround steak with kosher salt. Place in oven 5 to 6 inches from heat. Broil 12 minutes or until done.
Place steak on a wooden plank; discard kosher salt. Slice steak; surround with mashed potatoes.