Season the steaks Pat the filets dry and generously season both sides with salt and freshly ground black pepper.
Sear the steaks Heat the olive oil in a heavy skillet (preferably cast iron) over medium-high heat. Add the steaks and sear for 4–5 minutes per side for medium-rare, adjusting for your preferred doneness. Transfer to a plate and tent loosely with foil.
Sauté the shallots In the same skillet, reduce heat to medium. Add chopped shallots and sauté until translucent and soft, about 2–3 minutes.
Deglaze with brandy Carefully pour in the brandy. Stir and let the alcohol cook off, about 1–2 minutes, scraping up any flavorful bits from the pan.
Build the sauce Add the beef broth, cream, and crushed green peppercorns. Stir to combine. Bring to a gentle boil, then reduce to a simmer. Let the sauce thicken for 5–7 minutes, stirring occasionally.
Finish with butter Whisk in the butter until melted and silky. Taste and adjust seasoning if needed.
Return the steaks Place the rested steaks back into the pan. Spoon sauce over the top and cook for 1–2 minutes to warm through.
Serve and garnish Plate the steaks, drizzle generously with sauce, and garnish with chopped fresh parsley.