Rub steaks generously with salt and pepper. Set aside for at least 30 minutes at room temperature. Combine the butter, parsley, chives, and shallot with a fork in a medium bowl. Season lightly with salt and pepper, cover with plastic wrap and set aside.
Heat 2 tbsp. oil in a 12″ cast-iron skillet over medium-high heat. Add 2 steaks and cook, flipping once, until seared and medium rare, about 8 minutes. Transfer steaks to a plate and let rest for 5 minutes. Repeat with the remaining oil and steaks. To serve, smear each steak with 2 tbsp. of the herb butter.