Prep the Beef; Toss beef cubes with flour, salt, and pepper to coat.
Brown the Beef: Heat oil in a large Dutch oven/sauté pan over medium-high heat.Brown beef in batches, 3–4 minutes per side. Remove and set aside.
Sauté Aromatics: In the same pot, add onions and cook 5 minutes until soft. Stir in garlic and tomato paste, cooking for 1 minute.
Deglaze and Simmer: Pour in wine or broth and scrape up brown bits. Add beef broth, Worcestershire, thyme, paprika, and bay leaf.
Return Beef & Simmer: Add browned beef back to the pot. Bring to a simmer. Cover and cook on low for 1½ hours, stirring occasionally.
Add Vegetables: Add potatoes, carrots, celery, and parsnip (if using).Simmer uncovered for another 45–60 minutes, until veggies are tender and the stew thickens.
Finish Stew: Stir in peas and simmer 5 more minutes. Adjust seasoning with salt and pepper. Remove bay leaf and serve hot with crusty bread or over mashed potatoes. Finish & Serve