1) Place butter into a mixing bowl, season with salt and pepper and stir until blended and soft. Take a 30cm piece of cling film and lay it on the counter. Spoon the butter out onto the center of the cling film and place the chives in the center on top of the butter. Pull the edge over the butter mixture, and tightly pinch the ends, then holding the plastic wrap tightly at each end, pull the mixture towards you. This should create a tight sausage shape (or imagine rolling a sushi roll). Chives will be in the center surrounded by butter. Tie a knot on both ends of the butter roll and place into the freezer until you are ready to place it on top of your cooked filet.
2) Season the filets with a little salt and pepper. Heat a skillet over medium-high until the pan is hot then drizzle with olive oil. Place the filets into the pan and cook to medium-rare, about 5 to 7 minutes per side. Remove the pan from the heat and pour brandy into the skillet. Carefully tilt skillet towards the flame to flambe. When the flames burn off, remove the filets from the pan. Remove butter from freezer and cut 4 thin coins and place one on each filet. Serve steaks while hot.