Pat beef dry; sprinkle with salt and pepper.
Warm oil in a large pot over medium-high heat.
Brown beef in batches until well seared; remove to a plate.
Add onion, carrots, and celery; cook until softened.
Stir in garlic, tomato paste, thyme, and Italian seasoning; cook 1 minute.
Splash in Worcestershire and 1/2 cup broth; scrape up browned bits.
Return beef with remaining broth, tomatoes, and potatoes; bring to a boil.
Reduce heat, cover, and simmer until beef is tender, about 30 minutes.
Stir in mixed vegetables; simmer 6 to 8 minutes.
Taste and adjust salt and pepper; finish with parsley and serve.