01 - Pat beef cubes dry with paper towels. Toss beef in flour seasoned with salt and pepper until evenly coated.
02 - Heat vegetable oil in a large Dutch oven over medium-high heat. Brown beef cubes on all sides in batches, being careful not to overcrowd the pot. Transfer browned beef to a plate.
03 - Reduce heat to medium. Add chopped onions to the pot and cook for 3 minutes until softened. Add minced garlic and cook for 1 minute until fragrant.
04 - Stir in sliced carrots, parsnips, potato chunks, and celery. Cook for 3 to 4 minutes, stirring occasionally, to slightly soften the vegetables.
05 - Return browned beef to the pot. Add rinsed barley, bay leaves, thyme, and beef broth. Increase heat to bring the mixture to a boil.
06 - Reduce heat to low, cover tightly, and simmer for 1½ hours. Stir occasionally to prevent sticking and ensure even cooking.
07 - Remove the lid and continue simmering uncovered for 30 minutes. This allows the broth to reduce and thicken naturally while flavors meld together.
08 - Discard bay leaves. Stir in chopped fresh parsley. Taste and adjust seasoning with additional salt and black pepper if needed.
09 - Ladle hot stew into bowls and garnish with additional fresh parsley. Serve immediately while hot.