Cook the noodles: Bring a large pot of salted water to a boil. Cook egg noodles according to package directions until just tender. Drain and set aside. Toss with a tiny bit of olive oil to prevent sticking.

Prep the beef: Pat the sliced beef dry with paper towels. Season lightly with salt and pepper. Dry surfaces sear better, giving you more flavor.

Sear the beef: Heat 1 tablespoon butter and the olive oil in a large skillet over medium-high. Add beef in a single layer and sear quickly, 1–2 minutes per side. Do this in batches so you don’t crowd the pan. Transfer to a plate; it will finish cooking in the sauce.

Sauté onion and mushrooms: Lower heat to medium. Add 1 tablespoon butter, then the onion. Cook 2–3 minutes until softened. Add mushrooms and a pinch of salt. Cook, stirring occasionally, until browned and most liquid has evaporated, about 6–8 minutes.

Add garlic: Stir in the minced garlic and cook 30 seconds until fragrant. Don’t let it burn.

Deglaze: If using, add the wine or brandy. Scrape up browned bits from the skillet. Let it reduce by half, about 1 minute.

Build the sauce: Push the vegetables to the sides. Melt the remaining 1 tablespoon butter in the center. Sprinkle in the flour and stir to form a paste, coating the onions and mushrooms. Cook 1 minute to remove raw flour taste.

Add liquids: Whisk in the beef broth slowly, then add Worcestershire and Dijon. Simmer 3–5 minutes, stirring often, until the sauce thickens slightly.

Finish the beef: Return the seared beef and any juices to the pan. Simmer gently 1–2 minutes, just until the beef is cooked through but still tender. Avoid boiling.

Make it creamy: Reduce heat to low. Stir a few spoonfuls of hot sauce into the sour cream to temper it, then stir that mixture back into the skillet. Warm gently until smooth and silky. Do not let it boil or the sauce may curdle.

Toss with noodles: Add the cooked noodles and fold to coat evenly. Season with salt and pepper to taste.

Garnish and serve: Sprinkle with chopped parsley. Serve hot, with extra black pepper if you like.