Braising a lamb shank is like braising anything else. Give it a good sear followed by some solid cooking liquid and you're guaranteed favorable results.
I seared the shanks, then added some diced onion and cloves of garlic to the pan. Always remember to scrape up the leftover bits of meat after searing. That's the good stuff.
The braising liquid I used was stock, seasoned with fenugreek, black pepper, cinnamon and cayenne. The liquid goes over the shanks and onion/garlic mix, then in the oven at 325 degrees for an hour or two.