Loin Of Veal with Truffle Sauce

4 tb Vegetable shortening

1 Whole loin of veal*

1/2 lb Butter

1 Onion,large,chopped

1/4 lb Mushrooms,fresh**

2 Celery stalks,chopped

2 Tomatoes,quartered

1/2 c Chicken stock***

1 ts Salt

1/4 ts Pepper

1/4 ts Marjoram

2 Truffles,chopped****

* - loin of veal is to boned, rolled, and tied: 2-3/4 to 3 lb. ** - trim and chop mushrooms. *** - or water. **** - soak truffles in 1/4 cup cognac for 1-2 hours.