Brown the beef. Heat a large, heavy-bottomed pot or deep skillet over medium-high heat. Add ground beef and cook, breaking it up with a spoon, until browned and cooked through, about 5–6 minutes. Drain excess fat, leaving about 1 tablespoon in the pan.
Soften the onion. Reduce heat to medium. Add the diced onion and cook, stirring occasionally, until soft and translucent, about 3 minutes.
Add vegetables and broth. Add the potato cubes and carrot rounds to the pot. Pour in the beef broth and Worcestershire sauce. Add the bay leaf, thyme, and white pepper. Stir to combine.
Simmer. Bring the stew to a gentle boil, then reduce heat to medium-low. Cover and simmer for 15–18 minutes, or until the potatoes are completely tender when pierced with a fork.
Finish and season. Remove the bay leaf. Stir in the butter until melted. Taste and adjust salt as needed.
Serve. Ladle into bowls and top with fresh parsley if desired. Serve with crusty bread or flatbread on the side.
