Preheat oven to 350 degrees.
Choose a heavy casserole, preferably oval, large enough for 2 shanks. Of course you could make 1/2 recipe with only one shank.
Place onion, oil and butter in casserole and saute over medium heat until onions are pale gold color.
Add shanks, garlic, salt, pepper, and wine to casserole. Simmer for several minutes while tuning the shanks a couple of times....just trying to brown the shanks.
Add anchovies and broth, cover and bring to boil.
After reaching a boil, carefully transfer covered casserole to preheated oven and cook for 2 hours or until meat is extremely tender and falls off bone. Turn and baste shanks every 20 minutes while meat is cooking.
Remove and let rest for 15 minutes.
Garnish with parsley stems