Combine the carrots, celery, parsnips, onions and garlic in a 6-quart slow cooker. Sprinkle the beef on both sides with salt and pepper. Place on top of the vegetables. Add the wine, chicken broth, crushed tomatoes, thyme and bay leaf. Sprinkle with salt and pepper. Cover with the lid and cook on high for 6 hours, until the meat is tender.
Carefully remove the roast to a cutting board. Skim off any fat from the surface of the cooking liquid and remove the bay leaf. Transfer half of the vegetables and liquid to a blender and puree until smooth; stir back into the liquid and vegetables in the slow cooker to make a sauce. Slice the roast against the grain into 1/2-inch pieces. Serve the beef ladled with the sauce and vegetables.
When blending hot liquids, first let cool for 5 minutes or so, then transfer to a blender, filling only halfway. Put the lid on, leaving one corner open; this will prevent the vacuum effect that creates heat explosions. Cover the lid with a kitchen towel to catch splatters and pulse until smooth.