Preheat oven to 375 degrees.
Rinse and dry shanks and season liberally with salt and pepper. In a heavy-bottomed Dutch oven
with a lid, heat olive oil until smoking. Sear
shanks until dark golden brown over medium heat, about 15 to 18 minutes. Remove shanks and set aside. Add onion, garlic, rosemary and artichokes and cook until softened, about 8 to 10 minutes. Add olives
, wine, tomato sauce and chicken stock and bring to a boil. Replace lamb
shanks in pan and return to boil. Cover tightly and place in oven and cook for 1-1/2 hours, until fork tender. Remove and serve with soft polenta