Remove casings from sausage. Cook meat in nonstick skillet, breaking up with spoon, until lightly browned. Drain on paper toweling. Saute onion and garlic in oil in 3-quart saucepan until softened, 3 minutes. Add tomatoes, sausage, basil and salt. Simmer 25 minutes.
Meanwhile, cook lasagna noodles according to package directions. Rinse with cool water; drain.
Stir together ricotta, parsley, salt and nutmeg in small bowl.
Preheat oven to 375°F.
To assemble: Spread 1 cup sauce in 13 x 9 x 2-inch pan. Cover with layer of noodles. Spread 1 cup ricotta mixture evenly over noodles. Sprinkle with 1 tablespoon Parmesan and 2/3 cup mozzarella. Top with 1 cup sauce. Repeat layers twice more, ending with fourth layer of noodles, topped with remaining sauce and mozzarella. Cover with aluminum foil.
Bake in preheated 375°F oven for 1 hour. Remove foil. Bake 10 minutes. Let stand 10 minutes before cutting.
