Preheat oven to 350°F. Grease a 13 x 9-inch baking dish; set aside.
Cook lasagna noodles according to package directions. Drain, rinse with cold water and set aside.
Melt butter in a saucepan, add onion and saute until tender. Remove from heat and add cream cheese, cottage cheese, egg, basil, salt and pepper; mix well.
Combine soup, milk and wine in a medium bowl. Stir in shrimp and crab; mix well.
Arrange one-third of the noodles in baking dish. Top with half of the cheese mixture and then half of the seafood. Layer again with noodles, cheese mixture and seafood mixture. Finish off with a layer of noodles. Sprinkle with Parmesan cheese. Bake for 45 minutes, or until bubbly.
Top with cheddar cheese. Bake for 2 minutes longer or until cheese melts. Let stand for 15 minutes before serving. Garnish with tomato slices.