Remove the tenderloin from the freezer and, using an electric knife, cut the beef into 3/8 inch slices. Place slices of beef, one at a time, on a large piece of plastic wrap, fold the plastic over the meat, and lightly coat the beef and the top of the plastic wrap with water. Pound to no less than 1/8 inch thickness. Lightly brush each slice of beef on both sides with vegetable oil and sprinkle with salt and pepper, as desired. Set aside.
Heat a 12-inch cast-iron skillet over high heat for 3 to 4 minutes. Reduce heat to medium and turn skillet upside down over burner. Brush the pan lightly with oil. Place 2 to 3 slices of beef on the pan at a time and sear for 10 seconds on each side. Remove to an oven-proof platter and keep in warm oven. Repeat until all of the beef has been cooked. Serve immediately.