Heat oil in a large nonstick skillet over medium-high heat. Sprinkle beef with 1/2 t. salt and 1/4 t. pepper; dredge in flour. Add beef to pan; saute 2 minutes, browning on all sides. Place beef in slow cooker or crock pot.
Add onions and garlic to skillet; saute 5 minutes. Add wine to skillet, scraping pan to loosen browned bits. Place onion mixture in slow cooker.
Add broth, tomato paste, bay leaves, thyme, and tomatoes to cooker; top with zucchini and carrots.
Cover and cook on LOW for 8 hours or until beef is tender. Stir in remaining 1 t. salt and 1/4 t. pepper. Discard bay leaves and thyme sprigs.