How to Make It
In a bowl, combine the anchovies, butter, shallot, parsley, lemon zest, lemon juice and 1/4 teaspoon pepper. Wrap the butter in a piece of plastic wrap, shape into a 1-inch-thick log and freeze until firm.
Preheat the broiler. Arrange the steaks on a broiler pan, season with salt and pepper and broil for about 2 to 3 minutes per side for medium- rare. Transfer the steaks to plates, top each one with a 1/4-inch pat of the butter and serve immediately.