About 5 to 6 hours before serving: Preheat oven to 325°F.
Two hours before roast is done, cover with mixture of grated carrots, celery leaves, seasoned salt and pepper; continue roasting.
During last hour, cover meat loosely with foil, leaving thermometer uncovered.
Continue roasting until meat is of desired doneness.
When roast is done, let stand 15 minutes.
Cut crosswise, starting at backbone, between third and fourth rib bones.
Arrange halves on platter.
Garnish with carrot curls and parsley.