Add the beef stew meat to the slow cooker. Sprinkle the flour, salt, and pepper over the meat and toss until coated.
Place the carrots, potatoes, parsnips, onion, and garlic on top of the beef.
Stir the beef broth, tomato paste, and thyme together in a small bowl until smooth. Pour the mixture into the slow cooker.
Tuck the bay leaves into the liquid.
Cover and cook on low for 8 hours.
Remove the bay leaves and stir the stew before serving.