Rub steaks with oil; sprinkle with salt and pepper. Place on a rack on a broiler pan.
Broil until an instant-read thermometer inserted into the steak registers 140°F for medium-rare, 15 to 20 minutes total, turning once halfway through cooking. Transfer to a cutting board; let rest for 5 minutes.
Place herbs on a plate. Coat the edges of the steaks evenly with mustard; then roll the edges in the herbs, pressing gently to adhere.