01 - In a spacious bowl, thoroughly toss the beef cubes with all-purpose flour, kosher salt, and freshly ground black pepper until each piece is evenly coated.
02 - Heat 1 tablespoon of vegetable oil and 1 tablespoon of butter (or dairy-free margarine) in a large Dutch oven or heavy pot over medium-high heat. Brown half of the beef, turning occasionally to achieve a deep sear on all sides, approximately 5 minutes. Transfer the seared beef to a clean plate and repeat the process with the remaining oil, butter, and beef.
03 - Add the chopped onions, minced garlic, diced celery, sliced carrots, and sliced parsnips to the same pot. Sauté for 5 minutes, stirring occasionally, until the vegetables begin to soften and any browned bits from the bottom of the pot are scraped up.
04 - Stir in the tomato paste and cook for an additional minute, allowing it to caramelize slightly and enhance the stew's depth of flavor.
05 - Pour in the alcohol-free stout, scraping the bottom of the pot vigorously to deglaze and incorporate all flavorful residues. Add the low-sodium beef stock, Worcestershire sauce, brown sugar, bay leaves, and fresh thyme sprigs. Return all of the seared beef and any accumulated juices from the plate back into the pot.
06 - Bring the stew to a gentle simmer. Cover the pot with a lid and reduce the heat to low. Allow it to cook for 1 hour, enabling the beef to tenderize and the flavors to meld beautifully.
07 - Introduce the quartered baby potatoes to the stew and stir gently. Continue simmering, now uncovered, for another 1 hour or until both the beef and vegetables are exquisitely tender, and the sauce has thickened to your desired consistency.
08 - Carefully remove and discard the bay leaves and thyme stems from the stew. Taste and adjust the seasoning with additional salt and pepper as needed to achieve perfect balance.
09 - Serve the hearty Guinness-style alcohol-free beef stew hot, optionally garnished with a sprinkle of freshly chopped parsley for a bright finish.