How to Make It
Preheat oven to 350°F. Place turkey necks in a large saucepan; add water, and bring to a boil over high. Cover, reduce heat to medium-low, and simmer about 1 hour. Drain, reserving 4 cups cooking liquid. Remove and reserve meat from turkey necks, discarding bones.
Bring 3 cups reserved cooking liquid to a boil in a medium saucepan over high. Add rice; cover and bring to a boil. Reduce heat to medium-low, and cook until rice is tender, about 18 minutes. Remove from heat, and let stand, covered, 5 minutes.
Place sausage on a rimmed baking sheet; bake in preheated oven 20 minutes. Chop sausage.
Combine oil and flour in a large Dutch oven; cook over medium, stirring constantly, until roux is the color of caramel, 6 to 8 minutes. Slice scallions, separating green and white parts. Reserve sliced green parts of scallions. Add sliced white parts of scallions (about 3 tablespoons), chopped yellow onion, celery, bell pepper, parsley, garlic, and tomato sauce to the roux.
Cook, stirring often, until vegetables are tender, about 15 minutes. Add remaining 1 cup cooking liquid; bring to a boil. Add garlic salt, black pepper, paprika, thyme, and cayenne, stirring well. Add turkey, sausage, and ham, stirring well. Remove from heat. Serve over rice, and sprinkle each serving with reserved sliced green parts of scallions.