In a large saucepan, melt butter. Stir in the flour, bouillon, onion salt, 1 teaspoon pepper and white pepper if desired until smooth. Gradually stir in milk and broth. Bring to a boil; cook and stir for 2 minutes or until thickened. Add sausage; heat through. Combine the eggs, cottage cheese and remaining pepper.
Spread 1 cup sausage mixture in a greased 13-in. x 9-in. baking dish. Layer with three noodles, a third of the sausage mixture, half of the cottage cheese mixture and sauerkraut and 3/4 cup Monterey Jack. Repeat layers. Top with the remaining noodles and sausage mixture (dish will be full).
Cover and bake at 350° for 50-60 minutes or until a thermometer reads 160°. Sprinkle with remaining Monterey Jack. Bake 5 minutes longer or until cheese is melted. Let stand 15 minutes before cutting. Yield: 12 servings.