How to Make It
Preheat a grill pan. Season the steaks with salt and pepper. Grill them over moderately high heat for about 2 minutes per side for medium-rare. Transfer to a cutting board and let rest for about 5 minutes. Halve the baguettes lengthwise and cut them in half. Warm the bread in the grill pan. Spread the baguettes with 4 tablespoons of the butter. Thinly slice the meat and lay the slices in the baguettes. Brush the meat with the remaining 4 tablespoons of butter and serve.