In a large bowl, toss the beef strips with the all-purpose flour until evenly coated.
Heat the olive oil in a large skillet over medium-high heat. Add the beef strips in batches and brown on all sides, about 2-3 minutes per batch. Transfer browned beef to a plate.
In the same skillet, add the chopped onion and sliced mushrooms. Cook for 4-5 minutes until softened. Add the minced garlic and cook for 1 more minute. Remove from heat.
In a 6-quart crockpot, combine the browned beef, cooked onion and mushroom mixture, beef broth, Worcestershire sauce, smoked paprika, salt, and black pepper. Stir gently to combine.
Cover and cook on low for 6 hours, or until the beef is tender.
About 30 minutes before serving, cook the egg noodles according to package instructions until al dente. Drain and set aside.
Stir the sour cream into the crockpot mixture until fully incorporated. Do not boil after adding sour cream to prevent curdling.
Serve the beef stroganoff over the cooked egg noodles and garnish with chopped fresh parsley.