Season the steak with salt and pepper, then heat 1 tablespoon of the olive oil in a heavy skillet over medium high heat. Add half the meat to the pan and brown it quickly, about 2 minutes. Remove the first batch to a bowl and cook the rest of the meat. Remove and set all the meat aside. Add the remaining 1 tablespoon olive oil to the pan and add the onion, carrots, and mushrooms. Cook until the mixture is deep golden brown, about 5 minutes. Turn off the heat and add the brandy and 2 cups of the stock. Stir, scrape the bottom of the pan, and turn the heat to medium-high. Cook to reduce the liquid by about a third, 3 to 4 minutes.  In a small pitcher, make a slurry by mixing the remaining 1/4 cup stock and the cornstarch with a fork. Pour the slurry into the skillet and cook until the sauce thickens, about 1 to 2 minutes. Turn off the heat. Stir in the sour cream and Dijon. Add the beef and stir over low heat until the mixture is nice and piping hot. Taste and adjust seasonings as you like.  Serve over cooked noodles and sprinkle with parsley.