Season the beef with salt, black pepper, and paprika, coating all sides evenly.
Heat olive oil in a heavy pot over medium-high heat. Sear the beef until deeply browned on all sides. Remove and set aside.
In the same pot, sauté chopped onions until soft. Add minced garlic and cook for another minute.
Stir in tomato paste, thyme, Worcestershire sauce, and red wine (if using). Mix well.
Pour in beef broth and return the browned beef to the pot. Cover and simmer on low heat for 2½–3 hours until fork-tender.
Meanwhile, boil potatoes in salted water until completely soft. Drain and mash with warm milk and butter until creamy.
Once the beef is tender, remove the lid and allow the gravy to thicken slightly. Stir in butter for a rich, glossy finish.
Spoon creamy mashed potatoes into serving bowls. Place the tender glazed beef on top and drizzle generously with the rich gravy.
Garnish with freshly chopped parsley and serve hot!
