Step 1: In a large skillet, heat the olive oil over medium-high heat. Add the beef cubes and sear until browned on all sides. Remove the beef from the skillet and set aside.

Step 2: In the same skillet, reduce the heat to medium and melt the butter. Add the sliced onions and cook, stirring occasionally, until they turn a deep golden brown. This process should take around 15-20 minutes, as the onions need to caramelize slowly for maximum flavor.

Step 3: Once the onions are caramelized, add the minced garlic and cook for an additional minute until fragrant.

Step 4: Return the beef to the skillet, then add beef broth, Worcestershire sauce, thyme, black pepper, and a pinch of salt. Stir well to combine, and let the mixture come to a simmer.

Step 5: Cover and cook for 15-20 minutes until the beef is tender and the flavors have melded together.

Step 6: While the beef simmers, cook the egg noodles according to package instructions in a separate pot. Drain and set aside.

Step 7: Once the beef is fully cooked, add the noodles to the skillet and gently mix until the noodles are coated with the sauce. Adjust seasoning to taste.

Step 8: If you like, sprinkle shredded Gruyère or Swiss cheese on top and cover until melted, about 2-3 minutes.