Step 1: Sear the Beef : Heat olive oil in a skillet over medium-high heat. Season beef with salt and pepper and sear on all sides until browned.
Step 2: Prepare the Vegetables : In the same skillet, sauté onion, carrots, and celery until softened. Add garlic and cook briefly.
Step 3: Assemble in the Crockpot : Transfer beef and vegetables to the crockpot. Add crushed tomatoes, tomato paste, beef broth, red wine, bay leaves, oregano, thyme, salt, and pepper.
Step 4: Slow Cook : Cover and cook on low for 8 hours or high for 4 hours until beef is tender.
Step 5: Shred the Beef : Remove beef, shred with forks, then return to the sauce and stir well.
Step 6: Cook the Polenta : Bring water or broth to a boil. Gradually whisk in polenta. Reduce heat and cook, stirring, until thick and creamy. Stir in butter, Parmesan, and salt.
Step 7: Serve : Spoon polenta into bowls and top generously with beef ragu.