Bring a large pot of salted water to a boil. Add egg noodles and cook until al dente, about 8-10 minutes. Drain and set aside.

Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Sear thinly sliced beef sirloin for 3-4 minutes until brown. Remove and let rest.

In the same skillet, add another tablespoon of olive oil if necessary. Sauté chopped onions for 2-3 minutes until translucent. Add minced garlic and cook for 1 minute until fragrant.

Stir in sliced mushrooms and cook for 5 minutes until softened and golden brown.

Sprinkle all-purpose flour over the mushroom mixture and cook for 1 minute, stirring to thicken.

Gradually pour in beef broth and Worcestershire sauce, stirring until the sauce thickens, about 3-5 minutes.

Reduce heat to low and stir in sour cream, simming for 2 minutes. Season with salt and pepper.

Return the seared beef to the skillet, stirring to coat with the sauce. Cook for an additional minute to heat through.

Serve the stroganoff over the noodles or mix together. Garnish with freshly chopped parsley.