Trim any extra fat from the steak. Cut the steak into 4 pieces. Pound steak until it is 1/2-in. thick. Season steak on both sides with salt & pepper.
Coat a large skillet with non-stick cooking spray.
Heat skillet over medium-high heat. Brown steak, cooking for about 3 minutes on each side. Transfer to a 9x13x2 baking dish.
Stir flour into the drippings in the skillet. Stir in the tomatoes, celery, onion. corn, and oregano.
Bring to a boil and let cook for 1 minute, stirring constantly to remove any bits from the bottom of the pan. Pour mixture over the beef in the baking dish.
Cover and bake 60 minutes or until the meat is tender.