Heat the vegetable oil in a skillet over medium-high heat.
Brown the beef strips in batches, ensuring they are evenly cooked.
Once brown, transfer the beef to the crock pot.
In the same skillet, sauté the onions and garlic until translucent.
Add the sautéed onions and garlic to the crock pot along with sliced mushrooms.
Pour the beef broth and Worcestershire sauce into the crock pot.
Sprinkle in paprika and black pepper, and stir to combine.
Cover and cook on low for 6–8 hours, or high for 3–4 hours.
Once cooked, stir in sour cream until well blended.
Serve over egg noodles or rice and garnish with fresh parsley.