Heat oil in dutch oven and brown beef shanks. Remove meat from dutch oven and pour off fat. Return shanks to pot; add water, tomatoes, onions, salt and pepper. Bring to boil, reduce heat and simmer covered for one hour, stirring occasionally. Remove meat and cut into bit-size pieces. Skim fat from liquid; return meat to pot, add barley and bring to boil. Reduce heat simmer covered for 40 minutes. Add broccoli, carrots, mushrooms and thyme. Simmer covered for another 40 minutes.