01 - Preheat oven to 325°F.
02 - Pat the beef roast dry and season generously with salt and pepper.
03 - Heat a large Dutch oven or oven-safe pot over medium-high heat. Add a splash of oil and sear the beef on all sides until well-browned, about 4–5 minutes per side. Transfer to a plate.
04 - In the same pot, add onions, carrots, parsnips, celery, and garlic. Sauté for 5 minutes, scraping up any browned bits.
05 - Stir in tomato paste, cooking for 1 minute.
06 - Pour in the beer (if using), scraping up any remaining fond, then add the beef stock and Worcestershire sauce. Return the beef to the pot.
07 - Add potatoes, bay leaves, thyme, and rosemary. Bring to a simmer.
08 - Cover the pot and transfer to the preheated oven. Cook for 2.5–3 hours, until the beef is fork-tender and vegetables are cooked through.
09 - Remove the beef and vegetables to a platter. Skim excess fat from the cooking liquid and discard bay leaves and thyme stems.
10 - Slice or shred the beef. Spoon vegetables alongside and ladle some of the cooking liquid over the top. Garnish with chopped parsley before serving.