Preheat the oven to 450 degrees F. Rub the steak with the Worcestershire sauce, 1/2 teaspoon salt, and a generous amount of pepper; set aside.
Make the Yorkshire pudding: Whisk the eggs and milk in a large bowl; add the flour, scallions, cheese and 1/2 teaspoon salt and whisk to combine. Lightly brush a deep-dish pie plate with some of the butter, then whisk the remaining butter into the batter. Pour the batter into the prepared pie plate and bake until puffed and golden, 20 to 25 minutes.
Meanwhile, heat the vegetable oil in a large skillet over medium heat until very hot. Add the steak and cook until browned on the bottom, about 5 minutes. Flip the steak, reduce the heat to low and cover the skillet; continue cooking until a thermometer inserted sideways into the center of the steak registers 120 degrees F, 10 to 12 minutes. Transfer to a cutting board, tent with foil and let rest, 10 minutes. Add the tomatoes to the skillet, cut-side down; cover and cook until soft, 5 minutes. Thinly slice the steak against the grain and season with pepper. Cut the Yorkshire pudding into wedges. Serve with the tomatoes.