1. Remove sausage meat from casings. In 4-quart casserole or bowl, break up sausage meat; cover with casserole lid or large plate. Cook at high (100% power) 2 minutes; stir to break up sausage meat.
2. Add carrots, celery, onion, and garlic. Cover and cook at high 10 to 12 minutes, stirring every 4 minutes, until vegetables are tender. Stir in tomatoes with their liquid, wine, salt, and sugar; break up tomatoes with spoon.
3. Place veal roast, fat side down, in mixture in casserole. Spoon some mixture over roast. Shield top edges of roast with 1-inch-wide strip of foil. If roast is thin at one end, cover thin end with 3-inch square of foil to prevent overcooking. Cover; cook at high 10 minutes. Spoon tomato mixture over roast; cover and cook at medium (50% power) 30 minutes.
4. Turn roast fat side up; shield top edges with foil. Cover and cook at medium 30 to 40 minutes longer, spooning tomato mixture over roast every 15 minutes, until veal is tender.