Combine 2 tablespoons flour, salt, and pepper in a paper or plastic bag; add beef shanks, one at a time, and shake to coat.
Brown meat in hot shortening in Dutch oven.
Add tomato juice, parsley, and basil.
Cover and simmer 1 1/2 hours.
Add potatoes; cover and simmer 30 to 45 minutes more or till potatoes are tender.
Remove meat and potatoes; skim off excess fat from pan juices.
Add enough water to juices to make 1 cup liquid; return to pan.
Mix together 1/2 cup cold water and 2 tablespoons flour; stir into juices.
Cook and stir till thickened and bubbly.
Serve with potatoes.