Loosen cabbage core with paring knife. Plunge whole cabbage into pot of boiling water. Boil gently 10 minutes, or until leaves begin to soften. Drain cabbage; carefully remove large outer leaves (about 10). Shred inner leaves. While cabbage is boiling, break sausage casings and saute meat in oil until brown. Drain on paper towels. In large bowl, mix rice with sausage, scallions, celery, 1/2 cup parsley, and egg. Season to taste. Put about 2 tablespoons rice mixture in center of each leaf. Fold leaves, envelope style, and place seam side down (in one layer) in large skillet. Pour Savoy sauce over rolls. Sprinkle with shredded inner cabbage leaves. Cvoer skillet and simmer 30-40 minutes. Before serving, sprinkle with remaining one-half cup parsley.
SAVOY SAUCE: Puree 1 large can peeled tomatoes in blender or food processor with 1 teaspoon sugar. Add a generous pinch of dried rosemary and thyme, or fresh herbs of your choice.