Heat the olive oil over medium high heat and cook the mushrooms with salt and pepper. Add in onion and cook until onions are translucent.
Add in ground beef, breaking into small chunks with a spoon, and cook until no longer pink and beginning to brown. Stir in smoked paprika.
Add noodles and beef stock. Bring to boil, then reduce heat to low and cover. Simmer for 15-20 minutes, stirring occasionally so that all the noodles cook evenly.
When most of the liquid has cooked off, move the pot from the heat, and stir in 1/2 cup of the sour cream. Mix together until incorporated and season with salt and pepper.
Serve topped with chopped parsley and a dollop of the remaining sour cream.
FYI also tastes super good the next day- cold or reheated!