In a small bowl, combine butter, shallot, parsley, thyme, rosemary, mustard, 1/4 teaspoon salt and 1/4 teaspoon pepper and stir to combine. Gently roll butter mixture into 4 balls. Transfer to a plate and refrigerate until firm, about 20 minutes.
Meanwhile, rub both sides of the steaks with olive oil and season with 1/2 teaspoon salt and 1/4 teaspoon pepper.