Step 1

Melt 2 tablespoons butter in a large cast iron or stainless steel skillet over medium-high heat. Add the steak (uncut), seasoned generously with salt and pepper, and let it cook undisturbed for about 4 minutes on one side until nicely browned. Then flip the steak, and cook on the other side until browned, another 3 minutes, for a total of Remove steak from pan with a slotted spoon, and transfer to a separate plate. Set aside.

Step 2

Add 1 additional tbsp butter, chopped onions and saute for about 3 minutes. Add remaining tbsp butter, garlic and mushrooms, and cook for about 3 more minutes, or until mushrooms are juicy.

Step 3

Add flour to the pan, stir until no longer white. Add wine and let it cook down for 2 minutes. Then add beef broth, heavy cream, Worcestershire sauce, mustard and cayenne pepper. Combine well. Let the mixture simmer for 5 minutes, stirring occasionally. Season with additional salt and pepper if needed.

Step 4

Slice beef into thin slices, add back to the pan with the sauce and let it warm up for 2-3 minutes on low heat. Serve over noodles, rice, french fries or with vegetables.