Pat beef dry; season generously with salt & pepper.
Toss beef in flour; shake off excess.
Heat oil (med-high); sear beef 3–4 min/side in batches; set aside.
Add onion to pot; cook ~5 min until translucent.
Stir in garlic 30 sec until fragrant.
Add tomato paste; cook 2 min until darkened.
Pour in red wine; scrape browned bits; simmer 3–4 min.
Add broth, Worcestershire, bay leaves, thyme.
Return beef + juices; bring to gentle boil; reduce to low; cover 90 min.
Add carrots, potatoes, celery; cover; simmer 45–60 min until tender.
Taste; adjust salt & pepper.
If thin: whisk 2 tablespoon flour + ¼ cup cold water; stir in; simmer 5 min.
Remove bay leaves; rest 10 min; garnish with parsley (optional).