In a large skillet, melt butter over medium-low heat. Add onions and cook slowly (15–20 minutes) until golden and soft.
Push onions aside, increase heat to medium-high, and add beef. Cook until browned. Add garlic and cook 1 minute more.
Stir in Worcestershire, beef broth, thyme, salt, and pepper. Bring to a simmer.
Stir in egg noodles. Cover and cook 8–10 minutes until noodles are tender.
Stir in cheese until melted and creamy. Garnish with parsley and serve hot.
