1. Put everything but the flour and the tomato paste in a slow cooker; stir to combine.
2. Cover and cook on the low setting for 8 to 9 hours or on high for 4 to 5, until the beef is tender and the potatoes are just fork tender.
3. Stir the stew once or twice as it cooks, if possible. About 30 minutes before serving, transfer a ladleful of the broth to a small mixing bowl.
4. Add the flour and tomato paste and whisk until smooth. Stir the mixture into the stew and cook for the remaining half hour. Makes 6 to 8 servings.