In large skillet, melt butter over medium heat and saute onions and mushrooms for several minutes. Add garlic and stir until tender and onions are translucent. Remove from pan and set aside.
In the same pan, cook ground beef, breaking into small pieces, until brown. Drain excess grease.
Add in 1 cup of beef broth, Worcestershire sauce and stir to combine. Add salt and pepper to taste. Heat to boiling, stirring occasionally. Whisk in flour and remaining ½ cup beef broth. Stir to combine.
Add onion and mushroom mixture and return the sauce to boiling. Continue to stir until thickened.
Remove from heat and stir in sour cream.
Cook egg noodles as directed on package. Serve ground beef stroganoff on top of egg noodles.