Rinse the lamb brains. Dry them and cut into pieces. If using the spinal cords, parboil them, remove the skin, and cut them into small pieces. If using the sweetbreads and/or liver, trim, rinse, and dry.
Fill a bowl with water and add the lemon juice. One at a time, trim the artichokes. Cut each artichoke in half lengthwise and remove and discard any c