Heat olive oil in a large skillet over medium heat.
Add chopped onions and sauté until translucent.
Stir in minced garlic and cook for an additional minute.
Add sliced mushrooms and cook until browned, about 5-7 minutes.
Sprinkle flour over the mushrooms and mix well.
Gradually pour in vegetable broth, stirring to combine.
Reduce heat and let the mixture simmer for 5 minutes.
Add Worcestershire sauce and season with salt and pepper.
Stir in sour cream until creamy and heated through.
Serve over cooked pasta or rice, garnished with fresh parsley.