Place water and olive oil in large pot, bring water to a boil.
While water is coming to a boil, in large skillet melt butter over medium heat. Once melted add in mushrooms and onion. Sauté over medium high heat until onion is translucent. Place in bowl and set aside.
Place oil and beef strips in skillet, cook over medium high heat until outside is browned. Remove meat and add in bowl with onion and mushrooms.
In same skillet add in beef broth, Worcestershire sauce, and sour cream and blend well. Wisk in flour and salt.
Add back in beef, onion, and mushroom mixture and coat well.
Over medium heat, let simmer for about 20 minutes.
In boiling pot with water add penne pasta. Boil for 10 – 12 minutes or until tender. Drain pasta then rinse with hot water through a colander.
Place pasta in large serving platter. Pour sauce over pasta and serve.