Brown the beef on all sides in very hot oil. Remove the beef. Add onions and carrots to the same oil and cook for 5 minutes. Place beef and vegetables in a casserole. Add stock, tomato paste, bay leaf, parsley, thyme, pepper and salt. Cover and cook in a 180 degrees C. Oven for 2.1/2 hours until beef is tender. Discard bay leaf and parsley. Combine butter and flour in a small bowl, blending until smooth. Stir into liquid in the casserole. Cook 4 minutes until liquid is thickened into a sauce. Slice the beef, spoon over the sauce over the beef and serve with boiled potatoes and freshly cooked vegetables.