Cook noodles according to package directions. When finished cooking, drain and toss in 2 tablespoons butter to coat the noodles. Keep warm.
Season steak generously with salt and pepper. Heat large skillet (you could also use a wok), add olive oil and 1 tbls. butter. Add steak and cook until browned (stir a little while cooking), about 5 minutes (depending on how big your steak pieces are). Remove steak and set aside. In same pan, add onions, mushrooms, garlic and paprika. Cook, stirring occasionally until onions and mushrooms are soft and browned, and juices have evaporated (about 5-8 minutes). Return steak to pan with any of its juices. Stir to combine. Add parsley. Put steak/mushrooms/onions in serving bowl and keep warm while making the sour cream sauce.
Make the sour cream sauce:
Add white wine to pan to deglaze pan. Add broth. Stir well and cook over medium heat to reduce a bit. Remove from heat and whisk in sour cream. Season to taste with salt and pepper (I added a little more smoked paprika as well).
To serve, place buttered noodles on a plate, top with some steak, mushrooms and onions. Drizzle sour cream sauce on top of each serving. Garnish with additional chopped parsley and additional salt & pepper if desired.