01 - Pat the beef cubes dry with paper towels and season generously with salt and pepper on all sides.
02 - In a large Dutch oven or heavy pot, heat 2 tbsp oil over medium-high heat. Brown the beef in batches, adding more oil as needed. Transfer browned beef to a plate and set aside.
03 - Reduce heat to medium. Add onions, garlic, carrots, celery, and parsnips to the pot. Sauté for 5-7 minutes until softened, scraping up any browned bits from the bottom.
04 - Sprinkle flour over the vegetables and cook, stirring constantly, for 2 minutes to remove the raw flour taste.
05 - Return the beef to the pot. Stir in tomato paste, then pour in the alcohol-free stout and beef stock, scraping up any remaining browned bits from the pot bottom.
06 - Add Worcestershire sauce, bay leaves, thyme, and potatoes. Bring to a boil, then reduce heat to low. Cover and simmer for 1.5-2 hours, stirring occasionally, until beef is tender and sauce has thickened.
07 - Remove and discard bay leaves. Taste the stew and adjust seasoning with additional salt and pepper if needed.
08 - Garnish with chopped fresh parsley and serve hot with crusty bread, soda bread, or mashed potatoes.