Season beef with salt and pepper.
To a dutch oven over medium heat, sear the seasoned beef on all sides for about 3-4 minutes per side.
Once seared, remove from pot and lower heat to medium low.
Add the sliced onions to the same pot with butter, a pinch of salt, a pinch of pepper and dark brown sugar.
Continuously stir until the onions caramelize. This will take anywhere from 10-15 mins.
Stay close and keep stirring to prevent the onions from burning.
Once caramelized, add garlic and cook until fragrant.
Reserve 1/2 cup of the caramelized onions for the grilled cheese.
Sprinkle the remaining onions in the pan with flour and stir to allow the flour to be absorbed.
Deglaze the pan with white wine and Worcestershire sauce. Cook for 2-3 minutes.
Return the seared beef to the pot and add enough beef broth to cover.
Add thyme and bay leaves. Cover and cook on low for 1-2 hours. Or until the beef is fall apart tender.
Once cooked, reserve 1/2 cup of the tender beef. Shred and set aside.
Leave the soup to simmer on low heat until you’re ready to serve.