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. Slice or shred the beef. Spoon vegetables alongside and ladle some of the cooking liquid over the top. Garnish with chopped parsley before serving.