When shanks are browned and have been removed to plate, drain all but a film of fat from pan. Add carrots, celery, onion and bell pepper and cook, stirring, until vegetables begin to soften, about 10 minutes. Add garlic and cook, stirring, until garlic becomes very fragrant, about five minutes. Add tomato paste and cook, stirring, until you see dark streaks across bottom of pan where paste is browning, about five minutes. Add wine and stir to combine well.
Place shanks on top of vegetables.
Cover with sheet of aluminum foil to fit snugly against sides of pan. Cover tightly with lid and bake at 350 degrees 45 minutes. Remove lid and foil and add olives and good grinding of black pepper. Stir to mix well. Turn shanks and check level of liquid.