Preheat the oven to 350°F. Toss the beef in the flour, salt, and pepper until coated.
Heat oil in a Dutch oven over medium-high heat. Sear the beef in batches until browned on all sides. Remove and set aside.
Add more oil if needed then sauté the carrots, onion, celery, and garlic for about 5 minutes until softened. Add mushrooms here if using.
Add the Worcestershire sauce and red wine if using, scraping up any browned bits from the bottom of the pot.
Pour in the beef broth and return the beef to the pot. Add the potatoes, thyme, and bay leaves. Bring to a boil.
Cover and transfer to the oven. Cook for 2 hours until the beef is tender. If not tender after 2 hours continue cooking in 30-minute intervals until it is.
If adding frozen peas stir them in 30 minutes before serving. Remove the thyme and bay leaves, adjust seasoning, and serve garnished with fresh parsley.