Preheat oven to 225-250 degrees F. Thoroughly salt and pepper lamb shanks. In a roasting pan with rack, add water and place lamb shanks on rack. Bake uncovered for 2 hours.
While shanks are browning in oven, proceed with sauce. In a skillet, sauté onions, garlic and bell pepper until onions are opaque. Add crushed or diced tomatoes, wine and 1/2 of the parsley. Salt and pepper to taste.
Remove shanks from oven. Remove rack, drain liquid, and discard. Spread sauce evenly over shanks. Increase oven temperature to 350 degrees F. Cover lightly with lid or foil and place in oven.
Bake at 350 degrees for 1 hour. Remove lid or foil and return to oven for another 30 minutes.
Garnish with remaining sauce and parsley and serve with rice or bulgur pilaf.