Season the beef with salt and pepper.

Sear in hot butter in batches until browned but rare inside. Set aside.

Sauté mushrooms and shallots until golden.

Deglaze with brandy, add stock, and reduce by half.

Whisk in crème fraîche and mustard.

Return the beef to the pan just to warm through.

Serve over fresh egg noodles, garnished with snipped chives and a drizzle of truffle oil.