Peel, core and cut nashi in wedges. Place in saucepan with chicken stock, grated lemon rind and black pepper. Bring to the boil and cook covered for about 12 minutes or until nashi are tender. Remove nashi with slotted spoon, reserve stock.
Heat oil in a frying pan and cook veal cutlets until tender (about 6 minutes each side). Remove cutlets from the pan.
Deglaze the frying pan with dry sherry, add sage leaves (about 8 leaves) and pour into saucepan with reserved chicken stock. Return to heat, stir and reduce slightly. Strain and pour onto nashi. Add some fresh sage leaves (about 5 per serve).
Serve veal cutlets and nashi with steamed vegetables if desire.