Cut off artichoke stems; slice and reserve. Remove and discard hard outer leaves of artichokes. Cut sharp tips off remaining leaves with scissors. Slice off about 1 cm from top end of each artichoke. Open artichokes gently with your hands. Remove fuzzy chokes with a knife or melon-baller. Wash artichokes under cold running water. Slice lemon in half and rub over cut tops of artichokes. Set artichokes with cut part down on paper towels. Remove crusts from bread. Chop bread into small pieces and place in a medium bowl. Add half cup oil, parsley, garlic and salt and pepper. Mix well. Arrange mixture between artichoke leaves and in centers. Place artichokes and reserved stems in a large saucepan. Pour water about 3 cm deep in pan. Add 3 to 4 tablespoons oil. Bring water to a boil. Reduce heat to medium and cover pan. Cook artichokes 40 to 60 minutes, depending on size. If water evaporates, add a little more. There should be 4 to 5 tablespoons of sauce left in pan. If too much liquid is left, uncover pan and boil liquid down. Spoon sauce over artichokes and stems. Serve hot. Makes 4 servings.