Bring a large pot of salted water to a boil. Add the pasta and cook according to the package directions, then drain.
Meanwhile, whisk 3 tablespoons vegetable oil, the soy sauce, garlic, vinegar, sesame oil, sugar and red pepper flakes in a large bowl.
Add the cooked pasta, cabbage and cucumber to the bowl and toss to coat in the dressing. Set aside.
For the steaks: Heat 1 tablespoon vegetable oil in a large cast-iron skillet over medium heat. Season the steaks on both sides with the salt and pepper. Add 2 steaks to the hot skillet and place another heavy skillet or a dutch oven on top; cook about 30 seconds.
Remove the top skillet and continue to cook the steaks until browned and crusty, 2 to 3 minutes. Flip the steaks, then weigh them down again. Cook for another 30 seconds, then remove the weight and cook until browned, about 2 minutes for medium to medium-rare.
Transfer the steaks to a cutting board and let rest. Repeat with the remaining 1 tablespoon vegetable oil and 2 steaks. Slice the steaks. Serve with the sesame noodles and sprinkle with the scallions.
