Slice steak against the grain into approximately ¼” strips. Season with 1 tsp kosher salt and ¼ tsp black pepper.

Add 1 Tbsp olive oil to large skillet and heat over MED-HIGH/HIGH heat. Add steak slices in a single layer (you’ll likely need to do this in batches so as to not overcrowd the skillet).

Cook for 1-2 minutes, not stirring. Flip steak over and cook another minute or two until golden brown. Remove to plate and continue with remaining batches of beef. If skillet gets too dry, add another drizzle of oil.

To same skillet, add remaining 1 Tbsp olive oil and butter. Once melted, add onion and mushrooms and cook for 5-8 minutes, until onions have softened and mushrooms are getting golden.

Add garlic and cook another 30 seconds - 1 minute.

Sprinkle in flour, dried thyme, remaining ½ tsp salt and ½ tsp black pepper and stir well to coat. Cook for 1 minute.

Pour in beef broth slowly, stirring as you add it. Add Worcestershire sauce, cook, stirring often, until starting to thicken, about 5-7 minutes.

Stir in Dijon mustard and sour cream, then add cooked steak, along with any accumulated juices on the plate. Simmer another minute or two, or until sauce is thickened enough to thickly coat the back of a spoon.

Add green onions and parsley and cooked egg noodles and stir to combine well.

Serve hot, sprinkled with additional chopped parsley and a sprinkle of black pepper.