Sprinkle beef with salt and pepper; toss with flour. In a Dutch oven, heat oil over medium heat; cook beef and onion until lightly browned, stirring occasionally. Stir in curry powder, soy sauce, bay leaves and stock; bring to a boil. Reduce heat; simmer, covered, 45 minutes.
Stir in potatoes and carrots; return to a boil. Reduce heat; simmer, covered, until meat and vegetables are tender, 1-1¼ hours, stirring occasionally. Remove bay leaves; stir in vinegar. If desired, serve with rice.
