Heat a large skillet over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon. Drain excess fat and transfer the beef to the slow cooker.
Add the sliced mushrooms, chopped onion, sliced carrots, and minced garlic to the slow cooker.
In a small bowl, whisk together the red wine, beef broth, tomato paste, flour, thyme, salt, and pepper until smooth. Pour this mixture over the ingredients in the slow cooker.
Add the bay leaves, cover, and cook on low for 6 hours.
Remove and discard the bay leaves. Stir the mixture and sprinkle with fresh parsley before serving.