Season the steaks with salt and black pepper on both sides.

Heat olive oil in a large skillet over medium-high heat. Add the steaks and sear for about 4-5 minutes on each side for medium-rare, or adjust the cooking time based on your preferred doneness. Remove the steaks from the skillet and set them aside.

In the same skillet, reduce the heat to medium. Add 1 tablespoon of butter and sauté the garlic and shallots until softened, about 1-2 minutes.

Carefully add the brandy to the skillet. Be cautious as it may flame up. Allow the brandy to cook for about 1-2 minutes, allowing the alcohol to evaporate.

Add the beef broth, Dijon mustard, and Worcestershire sauce to the skillet. Stir well to combine and simmer for 2-3 minutes.

Stir in the heavy cream and the remaining tablespoon of butter. Cook for an additional 2-3 minutes, or until the sauce thickens.

Return the seared steaks to the skillet, coating them with the sauce. Cook for an additional 2 minutes, allowing the steaks to heat through.

Sprinkle chopped parsley over the steaks for garnish.

Serve the Steak Diane immediately, spooning the sauce over the steaks.