Begin by slicing the onions thinly. In a large pot, melt 2 tablespoons of butter over medium heat. Add the sliced onions and stir occasionally, cooking for about 30-40 minutes until caramelized.

While onions are caramelizing, heat a skillet over medium-high heat. Season the beef short ribs with salt and pepper, and sear in the hot skillet for about 3-4 minutes on each side until browned.

Once caramelized, add minced garlic, thyme, and bay leaves into the pot with onions. Pour in beef broth and stir well to combine.

Submerge the seared short ribs into the onion and broth mixture. Bring to a gentle simmer, cover, and reduce heat to low. Simmer slowly for about 3 hours.

After simmering, check the beef for tenderness. Remove bay leaves and shred short ribs in the pot. Stir well and serve topped with toasted bread.