Preheat and prep: Heat your oven to 325°F (160°C). Pat the beef dry with paper towels and season all over with salt and pepper.
This helps you get a good sear.
Brown the beef: Heat the olive oil in a large, oven-safe pot or Dutch oven over medium-high heat. Sear the beef in batches so you don’t crowd the pan, 2–3 minutes per side. Transfer browned pieces to a plate.
Sauté the aromatics: Lower heat to medium if needed.
Add onion and a pinch of salt. Cook 3–4 minutes until softened. Stir in garlic and cook 30 seconds, just until fragrant.
Build the base: Add tomato paste and cook for 1 minute, stirring to lightly caramelize it.
Sprinkle the flour over the onions and stir for another minute to form a light roux.
Deglaze: Pour in the red wine (if using), scraping up any browned bits from the bottom. Let it simmer for 1–2 minutes to reduce slightly. Add beef broth and Worcestershire sauce.
Whisk to smooth out any lumps.
Add veggies and herbs: Stir in carrots, celery, potatoes, mushrooms, thyme, rosemary, and the bay leaf. Return the browned beef and any juices to the pot. The liquid should just about cover everything; add a splash more broth if needed.
Simmer and bake: Bring the pot to a gentle simmer on the stove.
Cover with a lid and transfer to the oven. Bake for 1 hour 45 minutes to 2 hours, until the beef is fork-tender.
Finish the sauce: Remove from the oven. Stir in butter to gloss and round out the sauce.
Taste and adjust seasoning with salt and pepper.
Serve: Discard the bay leaf. Garnish with chopped parsley. Serve hot as-is, or spoon over rice, noodles, or mashed potatoes for extra comfort.