Toss the beef stew meat with the flour until evenly coated.
Heat the olive oil in a skillet over medium heat and brown the beef on all sides.
Place the browned beef in the slow cooker. Add the carrots, potatoes, onion, beef broth, tomato paste, garlic, thyme, bay leaves, salt, and pepper.
Stir to combine everything, then cover and cook on low for 7 hours.
Stir in the chopped kale, cover again, and cook on low for 30 more minutes until the kale wilts and the gravy thickens.